SPEECH COMMUNICATION LEARNING DIRECTORY · NOT AN ISCA PUBLICATION

SCOOT 2.0

Find your way into speech communication. Courses, lectures, tools and datasets, organized by the original SCOOT topics.

105 original resources · 122 extensions · 8 core topics

THE LEARNING DIRECTORY

What would you like to learn?

Start with a topic, or search for a course, tool, author or idea. Original resources and later additions are labeled separately.

About the original SCOOT catalog

Welcome to SCOOT, ISCA's guide to online training resources in Speech Communication.

Our aim is to help and encourage students who are learning about Speech Communication, who may come from a variety of backgrounds: phonetics, linguistics, computer science, electrical engineering… and be at different stages in their education, from first degree to Ph.D.

SCOOT provides students in speech communication with a guide to high-quality, up-to-date learning resources available on the internet, which can be tailored to their individual needs.

Please note that in many cases we are picking up material which has been prepared for particular cohorts of students taking particular modules, and therefore you will find material which is not relevant for you, e.g. details of assignments, lecture timings and so on.

SCOOT will never be finished.

Original wording from the 2026-08-31 snapshot · Visit the original SCOOT

BROWSE THE COLLECTION

The resource catalog

Original SCOOT entries   /   SCOOT 2.0 extensions

Overviews

Original SCOOT page: isca-speech.org/SCOOT-Overview

Here are some overviews of Speech Communication.

● Original SCOOT · 7
  • Lecture 1 in Roger Moore's course on Speech Processing introduces applications of speech processing. [Slides Audio]
  • Roger has also authored a series of YouTube videos on What Everyone Working on Spoken Language Processing Needs to Know about Spoken Language. [Part 1 Part 2 Part 3]
  • Roger's vision of the future is in his ISCA Distinguished Lecturer talk. [ISCA Distinguished Lecturer talk]
  • The Saras Institute 'History of Speech and Language Technology' holds a wealth of information about speech technology research and interviews with many of the pioneers. [History of Speech and Language Technology]
  • Lecture 5 in Roger Moore's course on Speech Processing, on 'The Nature of Speech', shows why speech is an interesting and challenging signal to process. [Slides Audio]
  • Simon King's Course on Speech Processing is a multimedia introduction covering the fundamentals of speech communication and introducing speech technology. It is part of Edinburgh's speech.zone. [Simon King's Course on Speech Processing speech.zone]
  • The Speech Kitchen includes an introductory speech and language processing course. [Speech Kitchen speech and language processing course]
✚ SCOOT 2.0 extensions · 3
Introduction to Speech Processing — Aalto University (Tom Bäckström et al.)

Open online course book underpinning Aalto's speech processing teaching: speech production and acoustics, analysis, coding, enhancement, transmission, recognition and synthesis, with interactive Python examples. Licensed CC BY-SA 4.0; designed for self-study and course adoption.

courseintrofree2022 (2nd edition)
ISCA Video Archive — International Speech Communication Association

ISCA's official archive of recorded conference content: Interspeech sessions from 2010-2022, Odyssey speaker and language recognition workshops (2010-2016) and invited lectures, streamed free via SuperLectures and YouTube, many with downloadable slides. Coverage currently stops around 2022.

video-seriesadvancedfree2010-2022 recordings, page still online
ISCA Archive — ISCA

Open-access repository of about 42,000 papers from some 400 ISCA conferences and workshops (1970-2026), including all Interspeech and Eurospeech proceedings plus SSW, Odyssey, SPSC, and Blizzard papers. Searchable by author and topic, with DOIs and BibTeX export.

toolintrofree2026, continuously updated

Sound

Original SCOOT page: isca-speech.org/Sound

● Original SCOOT · 3
  • Lecture 2 in Roger Moore's course on Speech Processing is an introduction to the physics of sound. [Slides Audio]
  • In Edinburgh's speech.zone, speech signals are covered in the Digital Speech Signals module. [Digital Speech Signals module]
  • This Introduction to Speech Acoustics from Listen Lab is a series of YouTube videos covering some aspects of acoustics, signal processing and phonetics. [Introduction to Speech Acoustics]

Signal Processing

Original SCOOT page: isca-speech.org/Signal-Processing

Speech signal processing transforms speech acoustics to features which represent speech information (for instance the distribution of energy over time and frequency), and vice versa.

● Original SCOOT · 6
✚ SCOOT 2.0 extensions · 8
Think DSP: Digital Signal Processing in Python — Allen B. Downey (Green Tea Press)

Free Python DSP textbook with a top-down, code-first approach: decomposing sounds into harmonics, spectra, the FFT, spectrograms, filtering, sampling, and LTI systems. Runnable Jupyter notebooks on GitHub. Free HTML and PDF, Creative Commons licensed; second edition in progress.

textbookintrofree2016; 2nd edition in progress
The Scientist and Engineer's Guide to Digital Signal Processing — Steven W. Smith

Steven Smith's 640-page DSP reference, free online in full: sampling, convolution, the DFT/FFT, and FIR/IIR digital filters, with low-math, intuitive explanations and 500+ figures. Browse chapters or download PDFs. Widely used practical reference.

textbookintermediatefree1997–2011, free online
MIT OpenCourseWare 6.003: Signals and Systems — MIT OpenCourseWare (Dennis Freeman)

MIT OpenCourseWare course on signal and system analysis: discrete- and continuous-time LTI systems, Fourier series and transforms, Laplace and z-transforms, sampling, and feedback. Full video lectures, notes, and problem sets with solutions. CC BY-NC-SA. Undergraduate core course.

courseintermediatefreeFall 2011
Digital Signal Processing (EPFL specialization) — EPFL (Prandoni & Vetterli), via Coursera

EPFL four-course specialization on discrete-time signal processing: signals as vectors, the DFT/DTFT, FIR/IIR filter design, sampling, quantization, and applications. Video lectures with Python/Jupyter exercises, taught by Prandoni and Vetterli. Access to course materials requires a paid Coursera enrollment or Coursera Plus (free trial and financial aid available); the instructors' textbook, Signal Processing for Communications, is freely available online at sp4comm.org.

courseintermediatepaidongoing
Introduction to Speech Features — Herman Kamper, Stellenbosch University

Short YouTube lecture series deriving classic speech features step by step: windowing, the short-time Fourier transform, mel filter banks and MFCCs. Slides are free on kamperh.com, which also hosts a companion dynamic time warping series with slides and a notebook.

video-seriesintrofree2021, still available
Audio Signal Processing for Machine Learning — Valerio Velardo (The Sound of AI)

YouTube series covering sound fundamentals, time- and frequency-domain features, Fourier and short-time Fourier transforms, mel spectrograms and MFCCs, combining intuition, math and librosa implementations in Python. Code and slides are free on GitHub; the updated v2 code targets current environments, while the legacy branch preserves the code used in the videos.

video-seriesintrofree2020, still widely used
librosa — librosa developers (Brian McFee et al.)

Python library for audio and music analysis: loading, spectrograms, mel features, MFCCs, pitch tracking, beat detection, and visualization utilities. The foundation of countless speech feature-extraction tutorials. v1.0.0 (first stable-API release) released August 2026; ISC license.

toolintrofree2026 (v1.0.0)
Purdue ECE 538: Digital Signal Processing I — Purdue University (Mike Zoltowski)

Public course materials on discrete-time signals and systems, correlation, Fourier analysis, sampling, and digital filters, with applications including speech processing. The Fall 2026 course page provides lecture notes, MATLAB demonstrations, and speech waveform examples. Posted materials are free to access; course enrollment and assessment use Purdue systems.

courseintermediatefreeFall 2026

Linguistics

Original SCOOT page: isca-speech.org/Linguistics

Linguistics is the scientific study of language and involves an analysis of language form, language meaning, and language in context. Psycholinguistics is the study of the relationships between linguistic behaviour and psychological processes, including the process of language acquisition. Phonetics is the study of speech sounds. Phonology is the organisation of speech sounds in a language.

See also: Linguistics (Wikipedia)

✚ SCOOT 2.0 extensions · 1
Essentials of Linguistics (2nd edition) — Catherine Anderson et al., eCampusOntario/McMaster

Open textbook with embedded video lectures, exercises, and quizzes. Covers phonetics (articulation, IPA transcription, acoustics) and phonology (features, rules), plus morphology, syntax, semantics, and psycholinguistics. Second edition (2022), CC BY-NC-SA licensed. Introductory undergraduate level, with a Canadian-English focus.

textbookintrofree2nd edition 2022

Psycholinguistics

Original SCOOT page: isca-speech.org/Psycholinguistics

Psycholinguistics, or psychology of language, is the study of the interrelation between linguistic factors and psychological aspects.

See also: Psycholinguistics (Wikipedia)

● Original SCOOT · 1
  • See Odette Scharenborg's Winter School presentation, particularly lecture 2. [Winter School presentation (the slide files listed there are currently offline)]

Phonology

Original SCOOT page: isca-speech.org/Phonology

Phonology is a branch of linguistics concerned with the systematic organization of sounds in languages.

See also: Phonology (Wikipedia)

● Original SCOOT · 2

Phonetics

Original SCOOT page: isca-speech.org/Phonetics

Phonetics is the study of the sounds of speech. It is concerned with the physical properties of speech sounds or signs (phones): their physiological production, acoustic properties, auditory perception, and neurophysiological status. Phonology, on the other hand, is concerned with the abstract, grammatical characterization of systems of sounds or signs.

In the case of oral languages there are three basic areas of study — articulatory, acoustic, and auditory phonetics — inter-connected through the common mechanism of sound, such as wavelength (pitch), amplitude, and harmonics. [adapted from Wikipedia]

● Original SCOOT · 3
  • The phoneme is 'the smallest unit of speech that distinguishes one word from another in a particular language'. The term is often misused in speech research: see Moore and Skidmore, On the use/misuse of the term 'Phoneme'. [On the use/misuse of the term 'Phoneme']
  • For a general coverage of the above, see the April 5 Stanford lecture by Andrew Maas. [Stanford CS224S syllabus]
  • The Virtual Linguistics Campus hosts a number of courses on YouTube, including two on phonetics. [Virtual Linguistics Campus]
✚ SCOOT 2.0 extensions · 3
Interactive IPA Chart (official) — International Phonetic Association

The International Phonetic Association's official clickable chart: click any symbol to hear it (recordings by Esling, House, Ladefoged, Wells) and see its phonetic description, IPA number, and Unicode value. Covers the full consonant, vowel, and diacritic inventory. Free.

toolintrofree2018 chart, maintained
Illustrations of the IPA (Journal of the IPA) — International Phonetic Association / Cambridge University Press

Peer-reviewed 'Illustrations of the IPA' in the Journal of the IPA: concise phonetic descriptions of individual languages, each with a segment inventory and a transcribed, recorded passage. A model for describing a language's sounds. The journal is now fully open access.

paperadvancedfreeongoing (journal now fully open access)
UCLA Phonetics Lab Archive — UCLA Phonetics Laboratory (link may be down · archived copy)

Audio archive of field recordings from hundreds of languages with word lists, connected speech, and phonetic transcriptions, much of it from Peter Ladefoged's UCLA fieldwork. Primary source material for studying the world's speech-sound inventories. Open to everyone, free download.

datasetadvancedfree2007 launch, still online

Articulatory Phonetics

Original SCOOT page: isca-speech.org/Articulatory-Phonetics

Articulatory phonetics: the study of the organs of speech and their use in producing speech sounds by the speaker.

● Original SCOOT · 4
✚ SCOOT 2.0 extensions · 4
Seeing Speech — University of Glasgow (six Scottish universities)

Interactive IPA chart where each sound links to MRI video, ultrasound tongue imaging, and 2D midsagittal animations of the vocal tract, showing how consonants and vowels are articulated. Built by six Scottish universities. Free, Creative Commons licensed (CC BY-NC-ND).

toolintrofree2018
Dynamic Dialects — University of Glasgow (six Scottish universities)

Articulatory accent corpus: synchronized ultrasound tongue and lip video with audio for a shared word list plus spontaneous speech from English speakers worldwide. Clickable accent map. Companion to Seeing Speech, built by six Scottish universities. Free for non-commercial use (CC BY-NC-ND).

datasetintermediatefree2018
Sounds of Speech — University of Iowa

University of Iowa resource with animated vocal-tract diagrams, step-by-step production descriptions, and audio/video for every consonant and vowel of American English, Spanish, and German. Free in a browser; optional paid mobile app (English only). Beginner phonetics self-study.

toolintrofreemaintained (HTML5 site)
Pink Trombone — Neil Thapen

Browser toy that synthesizes voice from a real-time physical model of the vocal tract. Drag the tongue, lips, and glottis to form vowels and consonants and hear the output immediately. Free, hands-on intuition for source-filter and articulatory synthesis.

toolintrofree2017, live

Acoustic Phonetics

Original SCOOT page: isca-speech.org/Acoustic-Phonetics

Acoustic phonetics: the study of the physical transmission of speech sounds from the speaker to the listener.

● Original SCOOT · 1
  • Lecture 8 in Roger Moore's Speech Processing course is about acoustic phonetics. [Slides Audio]
✚ SCOOT 2.0 extensions · 4
Praat: doing Phonetics by Computer — Paul Boersma, David Weenink & Anastasia Shchupak, University of Amsterdam

Free open-source software for speech analysis and synthesis: waveforms, spectrograms, and formant, pitch, and intensity tracking, plus TextGrid annotation and a scripting language. Cross-platform (Windows/Mac/Linux). The standard tool for phonetic measurement and teaching; continuously updated.

toolintermediatefree2026 (v7.0.02, continuously updated)
Corpus Phonetics Tutorial — Eleanor Chodroff

Chaptered web tutorial on automating acoustic analysis: Praat scripting, Kaldi and the Montreal Forced Aligner for forced alignment, AutoVOT for voice-onset-time, and bash basics. Code-based, reproducible workflows for measuring large speech corpora. Free; also published as a 2018 arXiv paper.

tutorialintermediatefree2015, updated 2023
Parselmouth — Yannick Jadoul

Python library exposing Praat's C/C++ algorithms (pitch, formants, intensity, spectrograms) as a natural Python API with NumPy integration, no Praat scripting required. Installed as praat-parselmouth. v0.4.7 released November 2025; GPL-3.0.

toolintermediatefree2025 (v0.4.7)
Montreal Forced Aligner — MontrealCorpusTools (McGill University)

Command-line forced aligner producing word- and phone-level time alignments from audio plus transcripts, with pretrained acoustic models and harmonized IPA dictionaries for dozens of languages, G2P, and model adaptation. v3.4.3 released October 2026; MIT.

toolintermediatefree2026 (v3.4.3)

Auditory Phonetics and Hearing

Original SCOOT page: isca-speech.org/Auditory-Phonetics

Auditory phonetics: the study of the reception and perception of speech sounds by the listener.

● Original SCOOT · 4
  • Lecture 4 in Roger Moore's Speech Processing course is about hearing. [Slides Audio]
  • Odette Scharenborg's ISCA Winter School presentation covers speech perception in adverse listening conditions. [ISCA Winter School presentation (the slide files listed there are currently offline)]
  • The MAD demos recreate a number of classic findings in hearing. They run in Matlab. [MAD demos]
  • The final lecture in the series by Professor E. Ambikairajah on YouTube is about modelling the auditory system and auditory masking (how the perception of one sound is affected by the presence of another sound). [Modelling the auditory system and auditory masking]
✚ SCOOT 2.0 extensions · 9
Auditory Neuroscience: Making Sense of Sound (companion site) — Schnupp, Nelken & King (MIT Press)

Companion site to the MIT Press book by Schnupp, Nelken, and King, with free sound demos and animations: cochlear mechanics and hair cells, pitch and the missing fundamental, sound localization, speech perception, and cochlear-implant simulations. Demos free; full book paid.

textbookintermediatefreemiumbook 2011; site maintained
An Introduction to the Psychology of Hearing (6th ed.) — Brian C. J. Moore (Brill)

Graduate and upper-undergraduate textbook (~420 pp.) on auditory perception: cochlear frequency selectivity, masking and critical bands, loudness, pitch and periodicity, temporal processing, spatial hearing, and speech perception. The standard psychoacoustics reference. Paperback from Brill (first published by Emerald); paywalled.

textbookadvancedpaid2013 (6th ed., current)
Auditory Demonstrations (ASA/IPO CD) — Houtsma, Rossing & Wagenaars (Acoustical Society of America / IPO Eindhoven)

Online mirror of the classic ASA/IPO CD (Houtsma, Rossing, Wagenaars): 39 demonstrations across ~80 WAV tracks with an explanatory PDF booklet, covering loudness, the dB scale, masking, critical bands, pitch, timbre and binaural effects. Playable and downloadable per track.

tutorialintrofree1987 (online mirror, live 2026)
Demonstrations of Auditory Scene Analysis (Bregman archive) — Albert S. Bregman & Pierre Ahad, McGill Auditory Lab (rehosted by The Music Lab)

McGill/Music Lab archive of Bregman & Ahad's 'Demonstrations of Auditory Scene Analysis' (1996 MIT Press CD) with a PDF booklet, illustrating streaming, grouping and perceptual organization of sound. Free MP3 downloads (zipped set) and per-track listening, plus scene-analysis theory pages.

tutorialintrofree1996 CD (archive live 2026)
PSYCHOACOUSTICS-WEB — Massimo Grassi et al., University of Padua

Browser-based tool from the University of Padua that runs adaptive psychoacoustic experiments—frequency, intensity and duration discrimination, gap detection, amplitude-modulation detection—via transformed up-down staircases (Levitt, 1971). Guest mode or free accounts; suitable for classroom or online use, no coding required.

toolintermediatefree2024, maintained
Human and Machine Hearing: Extracting Meaning from Sound — Richard F. Lyon (Cambridge University Press)

Author's free draft PDF of Lyon's 'Human and Machine Hearing' (Cambridge, 2017; 2018 errata-corrected version), covering cochlear filtering, gammatone/PZFC filterbanks and the CARFAC digital cochlea, linking auditory models to speech and machine-hearing front-ends. CARFAC code (MATLAB/NumPy/JAX) is available separately.

textbookadvancedfree2017 book; free 2018 draft; CARFAC v2 2024
The Auditory Modeling Toolbox (AMT) — Acoustics Research Institute, Austrian Academy of Sciences (ARI/OeAW)

Open MATLAB/Octave toolbox (GPLv3) with 60+ peer-reviewed auditory models: gammatone/ERB filterbanks, cochlear and auditory-nerve models, loudness, modulation and binaural localization, with bundled data for reproduction. Maintained by ARI/OeAW. Used to build speech front-ends and predict perception.

tooladvancedfree2024 (v1.6.0), maintained
Objective intelligibility & quality metrics: pystoi + pesq — Open source (M. Pariente; ludlows)

Open Python packages for perceptual speech-evaluation metrics: pystoi (STOI and extended STOI intelligibility) and pesq (ITU-T P.862 narrowband/wideband quality, MOS-LQO). pip-installable, operating on reference and degraded waveforms; widely used to evaluate speech enhancement and separation systems. pesq source: github.com/ludlows/PESQ (PyPI: pesq).

toolintermediatefree2023, maintained
NIDCD: Cochlear Implants & Hearing Health — National Institute on Deafness and Other Communication Disorders (US NIH)

US NIH institute's plain-language health pages on hearing: how cochlear implants work (microphone, processor, electrode array, auditory-nerve stimulation), who benefits, and how implants differ from hearing aids, with sibling pages on hearing aids and hearing loss. Last updated June 2024.

communityintrofreeupdated 2024

Prosodics

Original SCOOT page: isca-speech.org/Prosodics

Prosodics is the study of rhythm, stress and intonation in spoken language: the 'music' of speech.

● Original SCOOT · 1
  • Professors Nigel G. Ward and Gina-Anne Levow of ISCA's Special Interest Group on Speech Prosody have produced a comprehensive tutorial, with 400 slides and 29 YouTube videos. This is a university-level introduction to prosody, covering both fundamentals and applications. [Comprehensive prosody tutorial]
✚ SCOOT 2.0 extensions · 1
Speech Prosody conference (SProSIG) — ISCA Speech Prosody Special Interest Group

Biennial conference of ISCA's prosody SIG and the only recurring international meeting covering linguistic, psychological, social, and technological aspects of prosody; about 300 attendees. Speech Prosody 2026 (13th edition) took place 26-29 May 2026 at the University of Pennsylvania, Philadelphia; the conference meets in even-numbered years.

eventintermediatepaid2026

Speech Technology

Original SCOOT page: isca-speech.org/Speech-Technology

Speech Technology is conventionally divided into Speech Coding, Speech Recognition and Speech Synthesis. There are several software toolkits for training and deploying speech technology. 'Recipes' are provided as examples of how to use the toolkit on typical tasks. In recent years Speech Technology has been increasingly dominated by Deep Neural Nets. There is a separate Deep Neural Networks section below summarising these developments. Here are some overviews:

● Original SCOOT · 3
✚ SCOOT 2.0 extensions · 2
CS224S: Spoken Language Processing — Stanford University (Andrew Maas)

Stanford's quarter-length graduate course on spoken language technology, emphasizing dialogue and conversational systems: neural ASR, synthesis, affect detection, digital assistants and multilingual speech. Syllabus, slides and assignments are public; lecture videos are restricted to enrolled students. Individual CS224S lectures are also cited in the original SCOOT Phonetics, Speech Synthesis and Speech Recognition sections.

courseintermediatefree2025 (Spring offering)
Computational Models of Conversational Grounding (ESSLLI 2026) — David Traum and Kristiina Jokinen (ESSLLI)

Five publicly accessible lecture-note PDFs and a bibliography from an ESSLLI 2026 advanced course. Covers common ground, feedback and error handling in spoken dialogue, grounding in language models, multimodal interaction, and incremental and multiparty dialogue. Aimed primarily at PhD students; familiarity with dialogue and pragmatics is helpful. Posted learning materials are free to access.

courseadvancedfree2026

Speech Coding

Original SCOOT page: isca-speech.org/Speech-Coding

● Original SCOOT · 3
✚ SCOOT 2.0 extensions · 7
Digital Show & Tell — Xiph.Org Foundation (Chris 'Monty' Montgomery)

~24-minute demonstration video showing sampling, quantization, bit depth, and dither on real analog and digital bench equipment. CC BY-SA, subtitles in eight languages, demo source code downloadable. Grounds the digitization concepts every codec builds on.

tutorialintrofree2013, still hosted
Audio Signal Processing and Coding — Wiley (Spanias, Painter & Atti, Arizona State University)

Graduate reference on perceptual coding of high-fidelity audio: psychoacoustic masking, time-frequency analysis, quantization and rate-distortion, and the MPEG/AAC standards families, with MATLAB projects and 600+ references. Complements speech-specific coding material on the wideband-audio side.

textbookadvancedpaid2007
Opus Interactive Audio Codec (RFC 6716) — Xiph.Org Foundation / IETF

The royalty-free IETF-standardized codec behind WebRTC and most VoIP: hybrid SILK (LPC) + CELT (MDCT) design spanning 6–510 kb/s. Site links spec (RFC 6716), reference implementation, comparisons, and demo write-ups; releases 1.5–1.6 add neural DRED and bandwidth extension.

toolintermediatefree2026 (libopus 1.6.1)
Neural Speech and Audio Coding: Modern AI Technology Meets Traditional Codecs — IEEE Signal Processing Magazine (Minje Kim & Jan Skoglund)

Nine-page magazine survey bridging traditional and neural codecs: taxonomy from DNN-assisted hybrids (LPCNet-in-Opus style) to end-to-end RVQ models (SoundStream, EnCodec, DAC), plus quality-evaluation pitfalls. Frames neural codecs as compression systems, not just LLM tokenizers. Open on arXiv.

paperadvancedfree2024
A Real-Time Wideband Neural Vocoder at 1.6 kb/s Using LPCNet (demo write-up) — Jean-Marc Valin (Xiph.Org / Mozilla)

Interactive demo article building a 1.6 kb/s neural speech codec: LPC plus WaveRNN synthesis, with explicit pitch/energy/cepstrum quantization and bit-allocation tables, listening comparisons against Opus, MELP, and Speex, and BSD-licensed code (github.com/xiph/LPCNet). Companion demos cover RNNoise.

blogintermediatefree2019, still hosted
Descript Audio Codec (DAC) — Descript

MIT-licensed reference neural codec compressing 44.1 kHz audio to discrete codes at ~8 kb/s (~90x) via Improved RVQGAN (arXiv:2306.06546). Ships pretrained 16/24/44.1 kHz weights, CLI encode/decode, and full training scripts — a codec students can run and retrain.

tooladvancedfree2023 (v1.0.0; main branch unchanged since July 2023)
LRAC 2026 Data Preparation — Cisco Open Source / LRAC Challenge

Official data preparation tools for the Low Resource Audio Codec Challenge. The 2026 pipeline builds 24 kHz speech, noise, and room-impulse-response releases with separate training, validation, and evaluation partitions, manifests, and Kaldi/ESPnet exports. Public code and instructions document the upstream datasets' access requirements and terms; Common Voice access requires a Mozilla Data Collective account. The historical 2025 recipe is available as an archived release.

tooladvancedfree2026

Speech Synthesis

Original SCOOT page: isca-speech.org/Speech-Synthesis

Most attention has been paid to 'Text-to-Speech' applications, i.e. type in the words you want and have them spoken for you. Speech synthesis systems are evaluated in terms of intelligibility (how many words are correctly identified by listeners?) and naturalness (to what extent does the synthesis resemble a normal human voice?).

Synthesis from written text (orthography) involves 2 stages: Text Analysis – transform the text into an intermediate representation; Waveform Generation – render the speech acoustics from the intermediate representation. To a large extent these stages are independent.

● Original SCOOT · 15
Text Analysis
Waveform Generation — Classic Speech Synthesis
  • Classic speech synthesis was based on simulations of the vocal tract, with filters for the formants. The simulation was supplied with parameters for excitation, formant frequencies and amplitudes. There were tables specifying how the parameters should change with time for different phones. The technique was also called 'Speech Synthesis by Rule' or 'Formant Synthesis'. The best known systems were the Klatt Synthesiser (US) and the Holmes Synthesiser (UK). Tutorial papers for both systems are in the Smithsonian Speech Synthesis History Project (SSSHP) 1986–2002. See this link for Klatt and this link for Holmes. The Klatt synthesiser is familiar as the voice of Stephen Hawking, and provided the original 'DECtalk' and 'Apple Voices'. [Smithsonian Speech Synthesis History Project Klatt Mattingly 1974 (the original page's 'Holmes' link)]
Waveform Generation — Concatenative Synthesis
  • Speech is produced by joining recorded acoustic segments together. There are ways of doing this which fool the auditory system into believing it is hearing flowing speech from the same speaker, notably PSOLA (Pitch Synchronous Overlap and Add). See the May 22 lecture by Andrew Maas, starting at slide 18. [Stanford CS224S syllabus (archived copy)]
Waveform Generation — Parametric (HMM-based) Synthesis
Waveform Generation — DNN Synthesis
✚ SCOOT 2.0 extensions · 4
Speech Synthesis and Voice Cloning (Skoltech ISP'25) — Skoltech (Ilya Borovik)

Compact 2025 Skoltech Independent Study Period course in English: slide decks for eight lectures in three modules plus a companion code repository covering TTS fundamentals, audio representations, acoustic models, vocoders, voice conversion and expressive/multilingual synthesis, ending with a clone-your-own-voice group project. MIT-licensed; no lecture videos.

courseintermediatefree2025
Blizzard Challenge — SynSIG / CSTR, University of Edinburgh

Long-running shared task in speech synthesis: teams build voices from a common database, compared through large listening tests (naturalness, similarity, intelligibility). 2025 edition ran at SSW13. Older challenge data and listening-test results downloadable via free license forms; some recent corpora restricted to participants.

challengeadvancedfree2005-2025, next 2027
Towards Controllable Speech Synthesis in the Era of LLMs: A Systematic Survey — Xie et al. (EMNLP 2025)

Systematic survey of modern TTS: zero-shot voice cloning and control of emotion, timbre, and style via codec language models (VALL-E line, arXiv 2301.02111), diffusion, and flow matching, plus datasets and evaluation. Companion list at github.com/imxtx/awesome-controllable-speech-synthesis.

paperintermediatefree2024, updated 2025
Speech Synthesis Workshop (SSW) — ISCA SynSIG

ISCA's dedicated text-to-speech workshop series, an Interspeech satellite held since 1990 and biennial since 2019. SSW13 ran August 2025 in Leeuwarden, themed sustainable synthesis for language diversity, co-located with the Blizzard Challenge; SSW14 is set for Brazil, 2027. Proceedings are open in the ISCA Archive.

eventadvancedpaid2025, next 2027

Automatic Speech Recognition (ASR)

Original SCOOT page: isca-speech.org/Speech-Recognition

Research on Automatic Speech Recognition (ASR) dates back to the 1950s.

● Original SCOOT · 13
  • See Lecture 1 in the Columbia Speech Recognition course for an introduction. [Lecture 1 in the Columbia Speech Recognition course]
  • Preethi Jyothi, IIT Bombay, gives a recent overview talk at Microsoft (2017). [Overview talk at Microsoft]
  • There is an edX online course on Speech Recognition. This is an introductory course to principles of speech recognition, created by Jasha Droppo, Mike Seltzer and Andreas Stolcke as part of Microsoft's 'AI School', but really self-contained and not specific to Microsoft AI services. It's aimed at undergraduates wishing to learn the basic principles of speech recognition. [edX course on Speech Recognition (archived copy)]
  • Michael Picheny of IBM presents a review of progress in ASR in 'Speech Recognition: What's Left?' (2018, I think). [Speech Recognition: What's Left?]
  • Hermann Ney (Aachen) provides an excellent treatment of the development of ASR and related Speech Tech over 40 years. This is the ISCA Medalist keynote talk at Interspeech 2021. [ISCA Medalist keynote talk at Interspeech 2021]
ASR Methods — Dynamic Time Warping (DTW)
  • The first ASR technique to get anywhere: DTW is based on finding the best time-alignment between a stored template (e.g. the features for a known word) and a pattern (e.g. the features for an incoming word). See the Columbia Speech Recognition course, Lecture 2, from slide 95. [Columbia Speech Recognition course, Lecture 2]
  • This module on pattern matching in Edinburgh's speech.zone. [Pattern matching module]
ASR Methods — Hidden Markov Models (HMMs)
ASR Methods — Neural Networks
✚ SCOOT 2.0 extensions · 2
11-751/18-781: Speech Recognition and Understanding — Carnegie Mellon University (WAVLab; Fall 2026: Samuele Cornell & Jee-weon Jung)

CMU's graduate speech recognition course from Shinji Watanabe's WAVLab, spanning statistical foundations to end-to-end neural ASR and understanding, with ESPnet-based assignments. The Fall 2026 offering is taught by Samuele Cornell and Jee-weon Jung; the public page currently lists only logistics (instructors, time, room), and past offerings kept materials behind Piazza login.

courseadvancedfree2026 (Fall offering), taught annually
ASR: Automatic Speech Recognition (University of Edinburgh open course materials) — University of Edinburgh, School of Informatics (course organiser: Peter Bell)

Public materials for Edinburgh's 18-lecture ASR course: speech signal analysis, HMMs and Gaussian mixture models, context-dependent phone modelling, large-vocabulary decoding with weighted finite-state transducers, and hybrid and neural acoustic models, with slides for each lecture plus reading lists, labs, and coursework. Labs use the open-source OpenFst toolkit with Python. Course materials are licensed CC BY-NC-SA; lecture recordings require a university login.

courseadvancedfree2026 (lectures from 12 January 2026), taught annually

Deep Neural Networks for Speech Technology

Original SCOOT page: isca-speech.org/ANN-ASR

The best-performing systems at the time of writing (2024) are based on deep neural networks. These YouTube videos from MIT provide an introduction to DNNs.

● Original SCOOT · 17
Introductions to DNNs (MIT videos)
  • Basics of Deep Learning covers the basics of neural nets and how they are trained: gradient descent and back propagation. [Basics of Deep Learning]
  • RNNs and Transformers covers sequence modelling, recurrent neural nets, Long Short-Term Memory, Transformers and Attention. [RNNs and Transformers]
  • CNNs covers Convolutional Neural Networks — illustrated using vision, but the same principles apply to feature detection from speech audio. [CNNs]
  • Generative Modeling (e.g. GANs) covers generative models: the basis of modern generative AI systems. [Generative Modeling]
  • Diffusion models: covers diffusion models in the second part of the lecture (from 26:40 onwards), as well as some history and challenges related to neural networks. [Diffusion models]
DNNs for Speech Synthesis
DNNs for ASR
  • DNN feature extraction: Wav2vec and Wav2vec2 are schemes for 'Learning the Structure of Speech from Raw Audio'. A convolutional network is trained by auto-encoding (i.e. to predict the next item given the history). This unsupervised training is then followed by supervised training on a much smaller dataset. The resulting feature extractor outperforms conventional feature sets as a module within an ASR. Wav2vec2 was developed by Meta. A 'Lazy Science' guide to Wav2vec2. [A 'Lazy Data Science' guide to wav2vec 2.0]
  • Meta's guide to Wav2Vec2. [Meta's guide to wav2vec 2.0]
  • Sequence modelling: ASR is a sequence-to-sequence task. Such tasks can be handled by recurrent neural networks, where at each step the network has access to the next frame of input data and to feedback from the last step. Recurrent neural nets have some serious problems and in recent years they have been superseded by Transformer architectures using attention-based models, introduced by Google in a famous paper 'Attention Is All You Need'. Transformer models designed for speech recognition are usually based on the encoder-decoder architecture similar to seq2seq models. In more detail, they are based on the self-attention mechanism instead of the recurrence that is adopted by RNNs. In end-to-end ASR the transformation from audio to words is accomplished by DNNs alone, with no use of phonetic or linguistic knowledge. An animated explanation of the 'Attention Is All You Need' paper by Jean de Dieu Nyandwi of CMU. [Animated explanation of 'Attention Is All You Need']
  • Speech recognition: a review of the different deep learning approaches, by Ilias Papastratis. [Review of deep learning approaches Ilias Papastratis]
  • Digital Ocean: Review of End-to-end ASR. A Digital Ocean tutorial on end-to-end speech recognition. [End-to-end ASR tutorial]
  • Michiel Bacchiani (Google): Google research on end-to-end models for speech recognition. [Video linked by the original page (a third-party review of Google's Conformer paper)]
DNN Toolkits
  • PyTorch is a machine learning library based on the Torch library and used for applications such as computer vision and natural language processing. This series of YouTube videos talks you through how PyTorch works. This tutorial allows you to experiment with the basics in PyTorch. [PyTorch YouTube series PyTorch basics tutorial]
  • TensorFlow is another popular DNN toolkit. [TensorFlow course]
  • SpeechBrain is a community toolkit for open-source conversational AI, based on PyTorch. [SpeechBrain]
  • Whisper is an open-source neural net system that 'approaches human level robustness and accuracy on English speech recognition', created by OpenAI. [Whisper]
✚ SCOOT 2.0 extensions · 16
11-785: Introduction to Deep Learning — Carnegie Mellon University (Bhiksha Raj, Rita Singh)

Semester-long CMU deep learning course from speech faculty; lecture and recitation recordings are publicly viewable on the course YouTube channel, with slides posted each semester. The homework sequence culminates in an attention-based end-to-end speech recognizer, a common on-ramp to neural speech work.

courseintermediatefree2026 (Fall), offered every semester
Hugging Face Audio Course — Hugging Face

Hands-on course on transformers for audio: audio data handling and architectures, then building ASR, TTS and audio classification systems with the Hugging Face ecosystem. Text lessons with runnable code, quizzes and a free completion certificate; fully open source and free.

courseintermediatefree2023, open-source and still available
Building AI Voice Agents for Production — DeepLearning.AI with LiveKit and RealAvatar

One-hour short course (seven video lessons plus code examples) on production voice-agent architecture: modular STT-LLM-TTS pipelines versus realtime speech-to-speech APIs, latency budgeting, voice activity detection, turn management and handling interruptions. Free to watch (access currently free during the platform beta); the graded assignment requires paid membership.

courseintermediatefreemium2026 (updated July 17)
Deep Learning in Audio (DLA) — HSE University, Faculty of Computer Science

Graduate course repository updated each autumn; this link is the complete 2025 iteration (the 2026 iteration is being built on the repository's default branch): lecture and seminar notebooks on CTC-based ASR, source separation and denoising, TTS and neural vocoders, with demanding PyTorch homework. Lecture recordings are in Russian, with English recordings for some weeks; code and homework are in English.

courseadvancedfree2025 (autumn iteration; 2026 iteration in progress)
S3PRL — S3PRL community (NTU Speech Lab origins)

Self-supervised speech toolkit behind the SUPERB benchmark: one-line loading of wav2vec 2.0, HuBERT, WavLM, and dozens of other upstream models, plus downstream evaluation tasks. In declared maintenance mode (bug fixes, new upstreams) with commits into mid-2025. Apache-2.0.

tooladvancedfree2025, maintenance mode
Speech Trident: Awesome Speech LM, Representation, and Codec Papers — NTU Speech Lab (Kai-Wei Chang, Haibin Wu, Hung-yi Lee, et al.)

Curated, regularly updated reading list covering the three pillars of speech LLMs: self-supervised representation models, neural audio codecs (EnCodec, DAC, Mimi), and speech/audio language models, plus benchmarks and tutorial links. Hundreds of papers; updates through 2026.

communityintermediatefree2023, still maintained
Advancements in Spoken Language Models: Building upon Text-Based LLMs (talk) — Hung-yi Lee (National Taiwan University)

Recorded English-language overview lecture (September 2025) by Hung-yi Lee on how spoken language models are built on top of text LLMs — speech tokens, architectures, and open challenges. A gentle orientation before tackling the written surveys.

tutorialintrofree2025
Recent Advances in Speech Language Models: A Survey — Cui et al., CUHK (ACL 2025)

First comprehensive survey of end-to-end speech language models: tokenizers, architectures, training recipes, streaming and duplex interaction, capabilities, and evaluation metrics. Peer-reviewed at ACL 2025; companion paper list at github.com/dreamtheater123/Awesome-SpeechLM-Survey.

paperintermediatefree2024, updated 2025
On the Landscape of Spoken Language Models: A Comprehensive Survey — Arora, Chang, Chien, Peng, Wu, et al. (CMU/NTU/TTIC/Meta; TMLR)

Survey organizing the whole spoken-LM space — purely speech-trained models, speech-plus-text hybrids, and speech-aware text LLMs — by architecture, training stages, and evaluation choices, with open problems. Authored across CMU, NTU, TTIC, Meta; published in TMLR, revised April 2026.

paperadvancedfree2025, updated 2026
Recent Advances in Discrete Speech Tokens: A Review — Guo et al., SJTU / Microsoft Research

Systematic review of discrete speech tokens: acoustic codec tokens (EnCodec, DAC, Mimi line) versus semantic tokens from self-supervised models, with taxonomy, design trade-offs, and controlled experimental comparisons across token types. Accepted to IEEE TPAMI; the key reference on audio tokenization for speech LLMs.

paperadvancedfree2025
Self-Supervised Speech Representation Learning: A Review — Mohamed, Lee, Livescu, Watanabe, et al. (IEEE JSTSP)

Definitive journal review (IEEE JSTSP 2022, ~30 pages) of self-supervised speech representation learning: generative, contrastive, and predictive approaches including wav2vec 2.0, HuBERT, and WavLM, plus benchmarks and analysis methods. Pre-LLM, but explains the foundations every speech LLM builds on.

paperadvancedfree2022
wav2vec 2.0: A Framework for Self-Supervised Learning of Speech Representations — Baevski et al., Meta AI (NeurIPS 2020)

The canonical self-supervised speech paper: contrastive learning over masked, quantized latent speech yields representations that fine-tune to strong ASR from as little as ten minutes of labels. Read alongside HuBERT (arXiv 2106.07447) and WavLM (arXiv 2110.13900).

paperadvancedfree2020
Moshi: A Speech-Text Foundation Model for Real-Time Dialogue — Kyutai (Défossez, Mazaré, Grave, Zeghidour, et al.)

Canonical paper for real-time full-duplex spoken dialogue: a 7B speech-text foundation model using the streaming Mimi neural codec and Inner Monologue text-token prefixing, reaching about 200 ms practical latency. Open code and weights at github.com/kyutai-labs/moshi.

paperadvancedfree2024
Qwen2-Audio Technical Report — Qwen team, Alibaba Cloud

Technical report for a widely used open audio-language model handling speech, sound, and music inputs, with voice-chat and audio-analysis modes. Representative of the audio-understanding LLM family alongside SALMONN (arXiv 2310.13289). Code and weights at github.com/QwenLM/Qwen2-Audio.

paperintermediatefree2024
SeamlessM4T: Massively Multilingual and Multimodal Machine Translation — Seamless team, Meta AI

Canonical multilingual translation paper: one model performing speech-to-speech, speech-to-text, text-to-speech, and text translation plus ASR for roughly 100 languages, built on w2v-BERT 2.0 representations. Follow-up Seamless (arXiv 2312.05187) adds streaming and expressive translation.

paperintermediatefree2023
Ultravox (open speech LLM) — Fixie AI

Open-weight multimodal LLM for real-time voice: a trained projector feeds audio directly into open LLM backbones (Llama, Gemma, Qwen), skipping a separate ASR stage. Training and inference code public; v0.6/v0.7 releases (2025) cover 42 languages.

toolintermediatefree2024, still maintained

Toolkits

Original SCOOT page: isca-speech.org/Toolkits

Many speech researchers use software toolkits which implement popular algorithms, e.g. for defining and training an ASR or building a synthesiser. Toolkits often provide recipes for common tasks.

● Original SCOOT · 1
  • The Speech Recognition Virtual Kitchen aims to 'provide straightforward access to the tools and techniques used by advanced researchers' by the use of virtual machines, which 'provide a consistent, end-to-end environment for experimentation, without the need to install other software or data, and cope with their incompatibilities and peculiarities.' [Speech Recognition Virtual Kitchen]

ASR Toolkits

Original SCOOT page: isca-speech.org/ASR-Toolkits

● Original SCOOT · 13
HTK
  • The Hidden Markov Model Toolkit (HTK) is a portable toolkit for building and manipulating hidden Markov models, developed at Cambridge, UK and first released in 1989. The researchers most closely associated with HTK are Steve Young, Phil Woodland and Mark Gales. HTK is primarily used for speech recognition research although it has been used for numerous other applications including research into speech synthesis, character recognition and DNA sequencing. HTK is in use at hundreds of sites worldwide. [HTK (archived copy)]
  • The HTK book is a comprehensive guide, including tutorials and recipes. [HTK book (archived copy)]
  • A shorter tutorial by Giampiero Salvi is available from KTH. [KTH tutorial (archived copy)]
  • Recipes for the Wall Street Journal task. [WSJ recipes for HTK]
CMUSphinx
  • The Sphinx toolkit, originally developed from Kai-Fu Lee's thesis, embodies more than 20 years' work at Carnegie Mellon University. There are tools designed for low-resource platforms. It's free. [CMUSphinx]
  • There is a tutorial for CMUSphinx. [CMUSphinx tutorial]
  • A recipe for the Wall Street Journal task. [WSJ recipe for Sphinx]
Kaldi
✚ SCOOT 2.0 extensions · 9
ESPnet — ESPnet community (CMU WAVLab and partners)

PyTorch toolkit with Kaldi-style recipes for ASR, TTS, speech translation, enhancement, diarization, SSL, and singing synthesis across dozens of corpora, plus a pretrained model zoo. Apache-2.0; release 202610 shipped September 2026 (latest patch v.202610.post2, 24 Sep 2026).

tooladvancedfree2026 (release 202610.post2)
SpeechBrain — SpeechBrain project (Mila / Concordia University)

PyTorch conversational-AI toolkit with 200+ training recipes on 40+ datasets covering ASR, speaker recognition, enhancement, separation, and language modeling, plus pretrained HuggingFace models and extensive tutorials. v1.1.1 released August 2026; Apache-2.0. Also listed in the original SCOOT catalog under Deep Neural Networks › DNN Toolkits.

toolintermediatefree2026 (v1.1.1)
NVIDIA NeMo (Speech) — NVIDIA

NVIDIA's framework for training and deploying speech models: ASR (Parakeet, Canary, Nemotron streaming), TTS (Magpie), and speech LLMs with multi-GPU scaling. In 2026 the original NeMo repository was refocused on speech, audio and speech LLMs (last pre-split NeMo release: v2.7.3), with frequent model releases. Apache-2.0.

tooladvancedfree2026 (NeMo Speech 3.0, v3.0.0)
icefall (next-gen Kaldi) — k2-fsa team (Xiaomi and community)

Training recipes of the next-generation Kaldi stack, built on k2 (differentiable FSA/FST) and Lhotse: Zipformer transducers, CTC and MMI for ASR, plus TTS recipes. Trained models export to sherpa for deployment. Commits through mid-2026; Apache-2.0.

tooladvancedfree2026
whisper.cpp — ggml.ai (Georgi Gerganov)

Dependency-free C/C++ port of OpenAI's Whisper on the ggml tensor library: quantized CPU/GPU inference on laptops, phones, Raspberry Pi, and WebAssembly, no Python required, with bindings for many languages. v1.9.5 released October 2026; MIT.

toolintermediatefree2026 (v1.9.5)
faster-whisper — SYSTRAN

Python reimplementation of Whisper on the CTranslate2 inference engine: up to 4x faster than openai/whisper at equal accuracy, with 8-bit quantization, batched inference, and built-in VAD. Backbone of many open transcription apps. v1.2.1 released October 2025; MIT.

toolintrofree2025 (v1.2.1)
sherpa-onnx — k2-fsa team (next-gen Kaldi)

Deployment toolkit running ASR, TTS, speaker diarization, VAD, and enhancement fully offline via onnxruntime. Supports Android, iOS, Raspberry Pi, RISC-V, and x86 servers, with APIs in 12 programming languages. Frequent releases through 2026; Apache-2.0.

toolintermediatefree2026 (v1.13.8)
pyannote.audio — pyannoteAI / CNRS (Hervé Bredin)

PyTorch toolkit for speaker diarization: voice activity detection, segmentation, speaker embeddings, and the open pretrained community-1 pipeline on Hugging Face; a paid precision-2 API also exists. v4.0.7 released June 2026; code MIT.

toolintermediatefree2026 (v4.0.7)
jiwer — Jitsi (8x8)

Small Python package computing WER, CER, MER, and WIL/WIP between reference and hypothesis transcripts, with composable text-normalization transforms and alignment visualization; fast RapidFuzz C++ backend. v4.0.0 released June 2025; Apache-2.0.

toolintrofree2025 (v4.0.0)

Synthesis Toolkits

Original SCOOT page: isca-speech.org/Synthesis-Toolkits

● Original SCOOT · 5
Merlin
  • Merlin is a toolkit for building deep neural network models for statistical parametric speech synthesis, developed at CSTR Edinburgh by a team led by Simon King. It must be used in combination with a front-end text processor (e.g. Festival) and a vocoder (e.g. STRAIGHT or WORLD). Merlin comes with recipes to show you how to build state-of-the-art systems. Merlin is free software, distributed under an Apache License Version 2.0, allowing unrestricted commercial and non-commercial use alike. [Merlin]
  • This video tutorial for Merlin is from Simon King. [Merlin video tutorial]
Festival
  • Festival, developed at CMU (Alan Black) and CSTR Edinburgh (Simon King), 'offers a general framework for building speech synthesis systems as well as including examples of various modules.' It is multilingual and there are online demos. [Festival]
Festvox
  • Festvox, from the CMU speech group, 'aims to make the building of new synthetic voices more systemic and better documented, making it possible for anyone to build a new voice.' There are close connections to Festival. [Festvox]
  • Festvox offers documentation, including scripts explaining the background and specifics for building new voices for speech synthesis in new and supported languages; specific scripts to build new voices in supported languages, such as US and UK English; aids to building synthetic voices for limited domains; example speech databases to help build new voices; and links, demos and a repository for new voices. [Documentation Limited domains Example speech databases]
✚ SCOOT 2.0 extensions · 4
Piper (piper1-gpl) — Open Home Foundation (Michael Hansen)

Fast local neural TTS (VITS-based) optimized for Raspberry Pi-class hardware, with pretrained voices in dozens of languages; powers Home Assistant voice. Successor repo to rhasspy/piper, archived October 2025. v1.8.0 released September 2026; GPL-3.0.

toolintrofree2026 (v1.8.0)
F5-TTS — SWivid (Shanghai Jiao Tong University authors)

Zero-shot voice-cloning TTS using flow matching with a Diffusion Transformer, trained on 100k hours of multilingual data (Emilia). Provides training, fine-tuning, CLI, and Gradio inference. v1 base model released March 2025; code MIT, checkpoints CC-BY-NC.

toolintermediatefree2025 (v1 model), repo active 2026
CosyVoice — Alibaba (QwenAudio team, formerly FunAudioLLM)

LLM-based zero-shot TTS family (CosyVoice 2, Fun-CosyVoice 3) with full training, inference, and deployment stack, including streaming, vLLM, and TensorRT-LLM runtimes. Covers 9 languages plus 18 Chinese dialects. Fun-CosyVoice 3.0 open-sourced December 2025; Apache-2.0.

toolintermediatefree2025 (Fun-CosyVoice 3.0)
VERSA — CMU WAVLab

Evaluation toolkit wrapping 90+ speech, audio, and music metrics (MOS predictors, intelligibility, speaker similarity, WER, distributional measures) behind one Python interface with YAML configs; integrates with ESPnet. Actively developed; first tagged release v1.1.0 in September 2026; Apache-2.0.

tooladvancedfree2024, v1.1.0 in 2026

Databases

Original SCOOT page: isca-speech.org/Databases

Modern speech technology relies on databases (or corpora) for training applications based on machine learning. Corpus linguistics uses databases as a resource for language studies.

See also: Corpus linguistics (Wikipedia)

● Original SCOOT · 3
  • The European Language Resources Association (ELRA) is a non-profit organisation whose main mission is to make Language Resources (LRs) for Human Language Technologies (HLT) available to the community at large. To achieve this goal, ELRA carries out a wide variety of activities around LRs, including Identification & Distribution, Production & Validation, Technology Evaluation, and Information Dissemination on HLT. [ELRA Identification & Distribution Production Validation Technology Evaluation Information Dissemination]
  • The Linguistic Data Consortium (LDC) is an open consortium of universities, libraries, corporations and government research laboratories, based in the USA. LDC was formed in 1992 to address the critical data shortage then facing language technology research and development. [Linguistic Data Consortium]
  • Corpora can be very expensive, but many of the classic ones are free or relatively cheap, e.g. TIMIT, the Wall Street Journal corpus, and Resource Management. [TIMIT Wall Street Journal corpus Resource Management]
✚ SCOOT 2.0 extensions · 16
LibriSpeech — OpenSLR (Panayotov & Povey)

1,000 hours of 16 kHz read English audiobook speech from LibriVox, segmented and aligned, with standard clean/other train, dev and test splits. CC BY 4.0; direct tar.gz downloads with mirrors. The default first corpus for ASR coursework and baselines.

datasetintrofree2015, still hosted
Mozilla Common Voice — Mozilla Foundation

Crowdsourced read and spontaneous speech under CC0: over 42,000 hours across 295 languages (Scripted Speech v27, September 2026), plus a separate Spontaneous Speech set. Since October 2025 downloads are served exclusively through Mozilla Data Collective (free account). Primary source for low-resource-language ASR training and evaluation.

datasetintrofree2017, v27 in 2026
GigaSpeech — SpeechColab

10,000 hours of transcribed English from audiobooks, podcasts and YouTube, in graded XS-XL training subsets plus dev/test. The GitHub tooling is Apache-2.0, but the audio is a gated Hugging Face dataset: SpeechColab's terms of access (accepted with a free account) restrict audio use to non-commercial research and education. Standard corpus for training and benchmarking large supervised ASR models.

datasetintermediatefree2021, still maintained
Multilingual LibriSpeech (MLS) — Meta AI

About 50,000 hours of read LibriVox audiobook speech in eight European languages (about 44,500 hours English), CC BY 4.0. The linked Hugging Face dataset streams the seven non-English languages (about 6,000 hours); the English portion and the original archives are downloaded from Meta's servers, listed on OpenSLR (SLR94). Standard train and eval sets for multilingual ASR and increasingly for TTS.

datasetintermediatefree2020
YODAS v3 — WAVLab (CMU) / ESPnet

Over 1.1 million hours of multilingual web audio in 100+ languages, released under CC BY 3.0. The v3 release is distinct from YODAS v1 and v2. It includes transcripts and English translations where available, timing information, and audio-quality metadata; downloadable in WebDataset format.

datasetadvancedfree2026 (v3)
Emilia / Emilia-Large — Amphion (CUHK-Shenzhen)

In-the-wild speech for generative models: 101k hours (Emilia, CC BY-NC 4.0) plus 114k hours Emilia-YODAS (CC BY 4.0) in Chinese, English, Japanese, French, German, Korean, with transcripts, WebDataset format. Gated Hugging Face access; check the split licenses carefully.

datasetadvancedfree2024, Large 2025
LibriTTS-R — Google

Sound-quality-restored LibriTTS: 585 hours of 24 kHz English read speech from about 2,400 speakers with normalized text, CC BY 4.0, direct OpenSLR download (SLR141). The standard academic corpus for multi-speaker TTS training before scaling to web data.

datasetintrofree2023
VoxCeleb 1 & 2 — VGG, University of Oxford

Speaker recognition corpora: 1,251 (VoxCeleb1) and 6,112 (VoxCeleb2) speakers, over a million utterances from YouTube interviews, with standard verification trial lists. Audio access via request form on the official Oxford page; no blanket open license, research use.

datasetintermediatefree2017-2018, still distributed
AISHELL-1 — Beijing Shell Shell Technology

178 hours of read Mandarin Chinese from 400 speakers across accent regions, with manual transcripts, Apache 2.0, direct OpenSLR download (SLR33). The standard entry corpus and character-error-rate benchmark for Chinese ASR.

datasetintrofree2017
FLEURS — Google

n-way parallel read speech in 102 languages (roughly 10-12 hours each), built from FLoRes translation benchmark sentences. CC BY 4.0 on Hugging Face. The standard multilingual ASR/LID/speech-translation evaluation set, used for Whisper, MMS and Open ASR multilingual results.

datasetintermediatefree2022, still maintained
SUPERB — NTU, CMU, Meta, JHU and collaborators

Benchmarks frozen self-supervised speech representations (wav2vec 2.0, HuBERT, WavLM class) with lightweight task heads across ten tasks: ASR, speaker, emotion, spoken language understanding and more. Evaluated via the open-source s3prl toolkit (now in maintenance mode); public leaderboard and papers.

benchmarkadvancedfree2021, toolkit maintained
ML-SUPERB 2.0 — CMU / NTU and community

Multilingual successor to SUPERB: ASR and language identification over 154 languages and 200+ varieties, scored with metrics that emphasize worst-performing languages and accent/dialect robustness. Ran as an Interspeech 2025 challenge; data, baselines and results public.

benchmarkadvancedfree2024, challenge 2025
Dynamic-SUPERB (Phase-2) — NTU and 100+ community contributors

Collaboratively expanding benchmark of 180 instruction-following tasks across speech, music and general audio, spanning classification, regression and sequence generation, for universal spoken language models (ICLR 2025). Tasks and leaderboard hosted on Hugging Face; evaluation code and task-submission tutorial on GitHub.

benchmarkadvancedfree2024, code 2025
Open ASR Leaderboard — Hugging Face (hf-audio)

Continuously updated leaderboard ranking 80+ open and proprietary ASR systems by word error rate and inverse real-time factor across standard English test sets, plus multilingual and long-form tracks. Evaluation scripts open-sourced on GitHub (huggingface/open_asr_leaderboard); results updated continuously.

benchmarkintrofree2023, updated 2026
AudioBench — A*STAR I2R (Singapore)

Evaluation suite for audio-capable large language models: 50+ datasets covering speech understanding, voice/accent/emotion paralinguistics and audio-scene tasks, with LLM-as-judge scoring (NAACL 2025). Open-source toolkit plus live Hugging Face leaderboard; includes Southeast-Asian language and Singlish extensions.

benchmarkadvancedfree2024, still extended
Full-Duplex-Bench — National Taiwan University and collaborators

Benchmark for full-duplex spoken dialogue models: pause handling, backchanneling, turn-taking and interruption management, scored with automatic metrics. v2 (Feb 2026) adds a real-time automated multi-turn examiner; v3 code and data released May 2026, adding tool use under disfluent speech.

benchmarkadvancedfree2025, v3 in 2026

Beyond the original topics

Three areas of speech communication that the original SCOOT did not cover. Every entry here is a SCOOT 2.0 extension, kept separate from the original catalog.

Paralinguistics & Emotion

What speech carries beyond the words: emotion, speaker states and traits, and the benchmarks that measure them. A topic the original SCOOT did not cover.

✚ SCOOT 2.0 extensions · 8
Computational Paralinguistics: Emotion, Affect and Personality in Speech and Language Processing — Björn Schuller & Anton Batliner (Wiley)

Field-defining Wiley textbook (344 pages) on automatically recognizing speaker states and traits — emotion, personality, age, health, intoxication — from speech and language. Covers the taxonomy of paralinguistics, corpora, acoustic features, machine learning and evaluation, with a tutorial on the openEAR toolkit lineage.

textbookintermediatepaid2013
ComParE — Computational Paralinguistics Challenge series — Schuller et al. / INTERSPEECH & ACM Multimedia

Archive of the Computational Paralinguistics Challenge (15 editions, INTERSPEECH 2009–2021 and ACM Multimedia 2022–2023): yearly tasks on emotion, age, personality, sleepiness, intoxication, COVID-19, stuttering and vocalisations, with baseline papers, standard feature sets and winners. Site is plain HTTP; data via organisers.

challengeintermediatefree2009–2023 editions; site still online
openSMILE — audEERING

C++ audio feature extractor, the de facto standard in paralinguistics: computes the ComParE 2016 (6,373 features) and GeMAPS/eGeMAPS acoustic parameter sets used across the challenge literature. pip-installable Python wrapper (opensmile-python). Free for private, research and educational use; commercial use requires a license.

toolintermediatefree2010, still maintained (v3.0.2, 2023)
w2v2-how-to: dimensional speech emotion recognition with wav2vec 2.0 — audEERING (Wagner et al.)

Notebook tutorial for audEERING's public wav2vec 2.0 model predicting arousal, dominance and valence, fine-tuned on MSP-Podcast v1.7; weights on Hugging Face and Zenodo (CC BY-NC-SA 4.0, non-commercial). Companion TPAMI 2023 paper analyses transformer-based SER, cross-corpus generalisation and fairness (arXiv:2203.07378).

tutorialadvancedfree2022, model and paper 2023
EmoBox: multilingual multi-corpus SER toolkit and benchmark — Ma et al., SJTU X-LANCE

Multilingual SER toolkit and benchmark (INTERSPEECH 2024): data preparation plus SpeechBrain training recipes for 32 emotion corpora in 14 languages (294 hours total), with intra- and cross-corpus leaderboards comparing 10 pre-trained speech models. Code and processed metadata are public; some corpora require separate licenses or registration.

benchmarkadvancedfree2024
SER-datasets: a directory of speech emotion corpora — Ayoub Malek (SuperKogito)

Searchable, community-maintained table of 77 speech-emotion corpora (2002–2024) — IEMOCAP, CREMA-D, MSP-Podcast, RAVDESS, RECOLA and more — listing language, size, emotion labels, license and open/restricted access per dataset, with automated link checking. Companion GitHub repository accepts contributions.

datasetintrofree2020, updated 2024 (v4.0.0)
IEMOCAP: Interactive Emotional Dyadic Motion Capture database — USC SAIL (Busso et al.)

Multimodal corpus of roughly 12 hours of dyadic acted and improvised English dialogue from 10 actors, with audio, video, motion capture and transcripts, annotated with categorical emotions and valence/arousal/dominance. Academic access requires a verified institutional email and acceptance of USC's release license; commercial use is not permitted.

datasetintermediatefree2008, still distributed
Speech Emotion Recognition in Naturalistic Conditions Challenge (Interspeech 2025) — MSP Lab (Carlos Busso) / ISCA Interspeech

Successor to the Odyssey 2024 emotion challenge: categorical (eight classes, Macro-F1) and dimensional (arousal/valence/dominance, CCC) tracks over 324+ hours of naturalistic MSP-Podcast speech. Baseline code on GitHub and the final leaderboards remain online; data requires a free institution-signed academic license.

challengeadvancedfree2025

Clinical & Accessibility Speech

Speech-language pathology, disordered speech, assistive and accessible voice technology — where speech technology meets health. A topic the original SCOOT did not cover.

✚ SCOOT 2.0 extensions · 8
ASHA Practice Portal — American Speech-Language-Hearing Association (ASHA)

Curated, peer-reviewed clinical- and professional-topic pages from the field's US professional body, covering aphasia, dysarthria, voice disorders, stuttering and more with assessment, treatment and linked evidence. Free web reference orienting newcomers to clinical terminology and scope of practice.

communityintrofree2026, continuously updated
Making Audio and Video Media Accessible (W3C WAI) — W3C Web Accessibility Initiative (WAI)

Guidance resource on captions/subtitles, transcripts, audio description and sign language for media, with the WCAG requirements they satisfy and planning advice. Free, maintained (updated September 2024); defines what quality captioning for Deaf and hard-of-hearing users actually requires.

tutorialintrofree2024, maintained
TORGO Database of Dysarthric Articulation — University of Toronto & Holland Bloorview (Rudzicz et al.)

~18 GB corpus of aligned acoustic and 3D articulatory (EMA) recordings from 8 speakers with dysarthria (cerebral palsy or ALS) plus 7 matched controls, with transcriptions. Free for academic, non-profit use from the Toronto page; also distributed via LDC (LDC2012S02).

datasetadvancedfree2012, still distributed
Speech Accessibility Project (SAP) — University of Illinois Urbana-Champaign (Beckman Institute)

Large multi-etiology disordered-speech corpus (Parkinson's, ALS, cerebral palsy, stroke, Down syndrome, stuttering, hearing loss) for training accessible ASR. Access by proposal plus a signed data-use agreement. Backed by Amazon, Apple, Google, Meta and Microsoft; ongoing 2025 releases.

datasetadvancedfree2025, ongoing releases
DementiaBank (with ADReSS / ADReSSo challenges) — TalkBank / Carnegie Mellon University

TalkBank repository of audio, transcripts and analysis tools for language in dementia, including the Pitt corpus and the ADReSS (Interspeech 2020) and ADReSSo (2021) Alzheimer's-detection challenge datasets. Free with consortium membership via email registration; students need a faculty sponsor. As of October 2026 the DementiaBank page states it 'is under review for potential modification in compliance with Administration directives', so access terms may change.

datasetadvancedfree2024 challenges, maintained
SEP-28k: Stuttering Events in Podcasts — Apple Machine Learning Research

Open dataset of ~28,000 three-second podcast clips (plus ~4,000 FluencyBank clips) labeled for five stuttering event types (blocks, prolongations, sound/word repetitions, interjections) by three annotators. Labels and metadata on GitHub (dataset CC BY-NC 4.0); audio must be re-downloaded from the original podcast URLs, and as of October 2026 the Stuttering Is Cool and Strong Voices URLs return 404 (about 6,300 of 28,177 clips), while FluencyBank media require a TalkBank login.

datasetintermediatefree2021, maintained
Project Euphonia: Advancing Inclusive Speech Recognition through Expanded Data Collection and Evaluation — Google Research (Project Euphonia)

Open-access (CC BY) Frontiers in Language Sciences paper (June 2025) on Google Project Euphonia's multilingual disordered-speech data collection (adding Spanish, French, Japanese, Hindi to English), SLP-based quality review, and a meaning-preservation ASR evaluation metric. Links to released open-source tooling.

paperadvancedfree2025
ModelTalker Voice Banking — Nemours Speech Research Laboratory

Web-based voice-banking pipeline: people with ALS/MND record a sentence inventory (a ~300-sentence Gen3 set or a longer 3,000+ set) to build a personalized synthetic TTS voice for AAC devices. $100 to download a completed voice (free for US ALS patients via Team Gleason); donors and clinicians register free.

toolintrofreemium2026, active

Community, Conferences & Challenges

Conferences, challenges, summer schools and student programs — how to stop learning alone. A topic the original SCOOT did not cover.

✚ SCOOT 2.0 extensions · 13
VoicePrivacy Challenge — VoicePrivacy consortium (Inria, EURECOM, NII, et al.)

Biennial challenge benchmarking speaker anonymization: conceal speaker identity while preserving linguistic content and emotion. The fourth edition (2026) had English and multilingual tracks and concluded with a workshop at the SPSC Symposium co-located with Interspeech 2026 (26 September 2026); baselines, datasets, and evaluation code at github.com/Voice-Privacy-Challenge. Results, system descriptions, and workshop presentation materials are now available on the official site.

challengeadvancedfree2026 edition (since 2020)
ASVspoof Challenge and ASVspoof 5 Database — ASVspoof consortium (EURECOM, NII, University of Edinburgh, et al.)

Community challenge series for speech spoofing and deepfake detection running since 2015. ASVspoof 5 provides a freely available crowdsourced database of about 2,000 speakers and 32 TTS, voice-conversion, and adversarial attacks (paper: arXiv 2502.08857), with protocols and baselines.

challengeintermediatefree2024, ongoing series
INTERSPEECH (ISCA flagship conference series) — International Speech Communication Association (ISCA)

The largest annual conference on speech science and technology, spanning phonetics to neural speech models. Interspeech 2026 was held in Sydney (28 September-1 October 2026); next: São Paulo (29 August-2 September 2027), San Antonio (2028), Athens (2029). Students get reduced registration, volunteer positions, mentoring events, and eligibility for ISCA travel grants.

eventintermediatepaid2026, next 2027
ICASSP (IEEE conference series) — IEEE Signal Processing Society

IEEE's annual flagship signal processing conference; speech and audio are among its largest tracks. ICASSP 2026 (Barcelona, 4-8 May) featured over 4,500 papers, tutorials, and SP Grand Challenges (including URGENT) open to students. Next editions: Toronto 2027, Tokyo 2028. Student rates available.

eventintermediatepaid2026
IEEE ASRU and SLT workshops — IEEE Signal Processing Society (SLTC)

Two biennial single-track IEEE workshops that alternate yearly: ASRU (2025 edition in Honolulu drew a record 447 submissions) and SLT 2026 (Palermo, 13-16 December). Cover ASR, spoken language understanding, dialog, and speech foundation models. Small scale means posters get real senior-researcher traffic.

eventadvancedpaid2026
ISCA Student Advisory Committee (ISCA-SAC) and mentoring program — ISCA-SAC

ISCA's student-run committee (since 2004). Runs mentoring at Interspeech—topic round-tables (two mentors, 6-8 students) and one-on-one matching (both held in person at Interspeech 2026)—plus the Doctoral Consortium (12th edition, held 26 September 2026 at UNSW before Interspeech 2026), the Speech Pitch podcast, Students Meet Experts panels, and volunteer roles.

communityintrofree2026, active
ISCA Grants — ISCA

Grants for students and early-career researchers attending ISCA-organized or ISCA-supported conferences, workshops, and training schools; cover early registration and possibly accommodation. Require an accepted paper, documentation of other funding sought, and no prior ISCA grant; researchers from low-income countries or special situations may also apply.

communityintrofree2026, ongoing
ISCA Training Schools Program (summer/winter schools) — ISCA

ISCA-sponsored summer and winter schools, typically five days, training students and early-career researchers on selected speech topics. ISCA contributes up to 5,000 euros per school budget, mainly for inviting lecturers; attendees can separately apply for ISCA grants through the online portal. The linked page is the call for school organisers; individual schools are announced separately.

courseintermediatepaid2026, ongoing
CHiME Challenge — CHiME community

Long-running challenge series on speech processing in everyday environments, with data and baselines provided. CHiME-9 (results presented at the HSCMA&CHiME 2026 workshop, Barcelona, May 2026) had two tasks: multimodal conversation recognition from 360-degree video and audio (MCoRec) and conversational hearing enhancement (ECHI). CHiME-10, announced July 2026, has three tasks (ECHI-2, URGENT and SG-TSE) and opens on 4 February 2027.

challengeadvancedfree2026 (CHiME-9); CHiME-10 opens Feb 2027
URGENT Speech Enhancement Challenge — URGENT organizers (ICASSP 2026 SP Grand Challenge)

Third iteration, run as an ICASSP 2026 SP Grand Challenge (September 2025–May 2026; final rankings posted) on universal, robust, generalizable speech enhancement. Track 1: one unified system across diverse distortions, domains, and formats, with a 700-hour curated training set; Track 2: speech quality assessment. Data, baselines and leaderboards remain online; the next URGENT round runs as CHiME-10 Task 2 (opens February 2027).

challengeintermediatefree2026 (ICASSP 2026 edition, ended May 2026)
JSALT - Jelinek Memorial Summer Workshop — Johns Hopkins University CLSP

Annual residential summer program at Johns Hopkins (since 1995): a 2-week summer school followed by a 6-week team research workshop where dozens of international researchers tackle frontier speech and language problems. JSALT 2026 (the 12th Frederick Jelinek Memorial Workshop) ran 15 June-7 August 2026; topics for the next workshop are proposed each autumn. Teams include funded positions for graduate and undergraduate students.

eventadvancedfreeannual (2026 edition held)
ISCA SIG-SPSC and SPSC Symposium — ISCA Special Interest Group on Security and Privacy in Speech Communication

ISCA special interest group joining technical and humanities perspectives on speech security and privacy. Runs the annual SPSC Symposium (6th edition held 26 September 2026 with Interspeech 2026, Sydney, jointly with the VoicePrivacy 2026 workshop), which welcomes challenge-participant papers. SIG participation is free; symposium registration paid.

communityintermediatefreemium2026
IEEE Speech and Language Processing Technical Committee (SLTC) and newsletter — IEEE Signal Processing Society

The IEEE SPS technical committee behind ICASSP speech and language sessions and the ASRU/SLT and Odyssey workshops. Its free newsletter (latest edition: Winter 2025, December 2025) carries committee reports on ICASSP speech-area reviewing, SLTC elections and the ASRU/SLT workshops; the TC pages separately list calls for papers and job postings.

communityintrofree2026, ongoing

Spoken LLM Benchmark Atlas

Explore benchmarks for spoken language models, the capabilities they measure, and reported model results with links to the source papers.

444benchmarks
19categories
261models tracked
17,136sourced result cells

Counts from the 2026-10-07 atlas build; refreshed from the live atlas when available.

Open the Benchmark Atlas → · overview paper · data + scripts

Like the rest of SCOOT 2.0, it is AI-maintained; its own page carries the full method and disclosure. Send corrections to the same contact address with [Atlas] in the subject.