FAQ

Audio & speech

Nine open audio datasets for speech and sound models

From 1,000 hours of clean read speech to 10,000 hours of audiobooks, podcasts and YouTube and 29,300 validated hours in 295 languages, plus sound events, emotion and speaker identity.

Audio splits cleanly into four jobs: transcribe it, classify it, identify who is speaking, or read the emotion. Picking the wrong corpus for the job costs more time than any architecture choice.

LibriSpeech is the benchmark everyone reports, but it is read audiobook speech — clean, segmented and nothing like a phone call. GigaSpeech and Common Voice are the corrective.

Five of the nine are non-commercial, gated or both: GigaSpeech's audio, UrbanSound8K, ESC-50, RAVDESS and VoxCeleb. Check before you build a product on them.

A horizontal bar chart of validated hours per language in Common Voice release 27.0. Pashto (3,530 h), Catalan (3,392 h) and English (2,827 h) lead, followed by Kinyarwanda, Belarusian, Esperanto, German and French above 1,000 hours each, then Spanish, Kabyle, Basque, Uyghur, Luganda, Swahili and Persian between about 370 and 600 hours; a grey bar shows the 280 other locales combined at 8,470 hours.
One corpus, very different amounts of data per language: in release 27.0 the fifteen largest locales hold more than seven in ten validated hours, while the median locale has about ten. The headline hour count says little about the language you need, so look up your locale before you plan on it. Chart drawn by Dataset Finder from common-voice/cv-dataset · MPL-2.0 repository (release statistics); Common Voice audio CC0
DatasetModalitySizeLicenceBest for
Mozilla Common VoiceAudio42,600 hoursCC0Multilingual ASR
LibriSpeechAudio~1,000 hoursCC BY 4.0ASR benchmark
GigaSpeechAudioUp to 10,000 hoursResearch onlyScale ASR
Google Speech CommandsAudio~105,000 clipsCC BY 4.0Keyword spotting
AudioSetAudio2M+ annotated clipsCC BY 4.0 (labels only)Sound events
UrbanSound8KAudio8,732 clipsCC BY-NC 4.0Urban noise
ESC-50Audio2,000 five-second clipsCC BY-NCFew-shot audio
RAVDESSMultimodal7,356 filesCC BY-NC-SA 4.0Emotion recognition
VoxCelebAudio1M+ clipsGated accessSpeaker ID
Licences in this shortlist — computed from the 9 datasets below. Red marks licences that are unclear or restricted; amber marks non-commercial, share-alike or mixed terms.
Six spectrogram panels of the same short audio clip arranged in two columns, titled dB, dB power, dBFS, dBFS power, 'dB, ref=1e-2' and 'dB power, ref=1e-2'; each has a log-spaced frequency axis from 0 to 8192 Hz, a time axis from 0 to about 4.8 seconds, a magma colormap and its own colorbar.
The same audio rendered under six decibel and scaling choices. A spectrogram is not the data — it is a rendering decision, and a model trained against one of these does not transfer to another. Image: librosa/librosa · ISC repository
№ 01

Mozilla Common Voice

AudioASRPublic domain
Size
~42,600 recorded hours (29,300 validated), 295 languages
Licence
CC0 1.0

Mozilla's crowdsourced speech corpus: tens of thousands of hours of MP3 clips with TSV metadata, about 42,600 recorded and 29,300 validated hours across 295 languages in release 27.0 (data collected to September 2026). Contributors read sentences aloud in their own accents and recording conditions, which is why models trained on it survive contact with real microphones.

What to train on it

Multilingual speech recognition, and accent-robustness testing for an ASR model trained on cleaner data.

Source: innovatiana.com/datasets

№ 02

LibriSpeech

AudioASR
Size
~1,000 hours
Licence
CC BY 4.0

About 1,000 hours of read audiobook speech in FLAC with TXT transcripts. Clean, well-segmented and the default benchmark for English ASR — if you report word error rate, this is the number people expect to see.

What to train on it

English ASR training and the baseline WER figure every reviewer will ask for.

Source: innovatiana.com/datasets

№ 03

GigaSpeech

AudioASRNon-commercial
Size
Up to 10,000 hours
Licence
Apache 2.0 for metadata and code; the audio is gated and for non-commercial research and education only

Up to 10,000 hours of transcribed audio in WAV and Opus, drawn from audiobooks, podcasts and YouTube. An order of magnitude more than LibriSpeech, and far messier — which is the point if your model has to handle spontaneous speech. SpeechColab does not own the audio copyright, so downloading the audio means agreeing to its non-commercial research and education terms.

What to train on it

Large-scale ASR pre-training where spontaneous, noisy speech is the target domain. Access is gated, and the audio terms are non-commercial.

Source: innovatiana.com/datasets

ESC-50meta/esc50.csv · lines 2, 57, 64
filenamefoldtargetcategoryesc10src_filetake
1-100032-A-0.wav10dogTrue100032A
1-172649-A-40.wav140helicopterTrue172649A
1-17367-A-10.wav110rainTrue17367A
ESC-50's metadata: every five-second clip carries its cross-validation fold, its class and the Freesound recording it was cut from. Fragments of one recording are kept in the same fold, so use the folds as given — a random split puts near-identical audio on both sides. From the dataset: karolpiczak/ESC-50 · meta/esc50.csv · CC BY-NC (these three rows are ESC-10 clips, CC BY)
№ 04

Google Speech Commands

AudioClassification
Size
~105,000 clips
Licence
CC BY 4.0

Around 105,000 one-second WAV clips of single spoken words. Built for wake-word and command recognition on constrained hardware, so the clips are short, the vocabulary is small and the models that win are tiny.

What to train on it

Keyword spotting and on-device voice commands where latency and model size matter more than vocabulary.

Source: innovatiana.com/datasets

№ 05

AudioSet

AudioTagging
Size
2M+ annotated clips
Licence
CC BY 4.0 for the labels (the ontology is CC BY-SA 4.0); the audio stays on YouTube under its owners' rights

Over two million annotated audio clips across a large ontology of sound events, released by Google. The labels are CC BY 4.0 but the audio itself stays on YouTube, so ingestion is a real engineering step rather than a download.

What to train on it

General audio event detection and tagging — the closest thing the field has to ImageNet for sound.

Source: innovatiana.com/datasets

№ 06

UrbanSound8K

AudioClassificationNon-commercial
Size
8,732 clips
Licence
CC BY-NC 4.0 (Zenodo download; the project site cites 3.0)

8,732 WAV clips of urban sounds — sirens, drilling, dogs, street music — organised into ten classes with a pre-defined ten-fold split. Use the published folds; results computed on a random split are not comparable to anything.

What to train on it

Environmental sound classification and urban acoustic-scene work. Non-commercial licence, so keep it to research.

Source: innovatiana.com/datasets

Line chart of validation WER (about 0.13 to 0.43) against epochs (0 to 70) for three runs: from_scratch (blue) starts highest near 0.43, finetune_from_en (orange) near 0.31 and finetune_from_ssl (green) lowest near 0.23. All fall steeply over the first 20 epochs and flatten between about 0.14 and 0.16, with orange lowest.
Validation word error rate while training a Kinyarwanda recogniser on Common Voice, which holds more than 2,000 hours of the language: from scratch, or starting from an English or a self-supervised checkpoint. All three settle near 0.14 to 0.15, and the English start finishes lowest. NVIDIA's notes add that a pretrained start matters most when the language has little data. Image: NVIDIA/NeMo · Apache-2.0 repository
№ 07

ESC-50

AudioClassificationNon-commercial
Size
2,000 five-second clips
Licence
CC BY-NC

2,000 five-second clips across 50 environmental classes — exactly 40 examples per class. The deliberate scarcity makes it the standard testbed for few-shot and transfer approaches in audio.

What to train on it

Few-shot audio classification. Non-commercial licence, so keep it to research.

Source: innovatiana.com/datasets

№ 08

RAVDESS

MultimodalEmotionNon-commercialShare-alike
Size
7,356 files
Licence
CC BY-NC-SA 4.0

7,356 WAV and MP4 files of actors speaking and singing in a controlled set of emotional states. Acted rather than spontaneous, which makes the labels clean and the generalisation to real emotion an open question worth measuring.

What to train on it

Speech emotion recognition, and audio-visual fusion since both modalities are aligned. Non-commercial and share-alike.

Source: innovatiana.com/datasets

№ 09

VoxCeleb

AudioSpeaker ID
Size
1M+ clips
Licence
CC BY 4.0 · request access

Over a million clips of human speech collected from interview footage, covering thousands of speakers in uncontrolled conditions. Speaker identity rather than content is the label, and the background noise is a feature, not a flaw.

What to train on it

Speaker identification and verification. The audio-visual files are released on request. The dataset is CC BY 4.0, offered for research purposes, but copyright in the underlying videos stays with their original owners, so clear any commercial use separately.

Source: innovatiana.com/datasets

A floor plan of a recording studio: the actor's position in front of a green screen, a microphone 20 cm away, a laptop and video camera 120 cm further back, two speakers in the rear corners, two lights at 212 cm on the diagonals and a third centred below the camera.
The studio used to record RAVDESS: the actor 20 cm from the microphone in front of a green screen, with lights, camera and speakers at fixed distances for every session. Fixed conditions make an acted corpus clean and consistent, and also explain why a model trained only on it can struggle with noisy, real-world audio. Image: Fig 2 of the article · CC BY 4.0 · from Livingstone & Russo 2018, PLOS ONE, “The Ryerson Audio-Visual Database of Emotional Speech and Song (RAVDESS)”, doi:10.1371/journal.pone.0196391

How this list was put together

Every entry is drawn from Innovatiana's open-dataset catalogue and links back to its page, where the full licence text and size string are published.

Hour counts and clip counts are quoted as published; where a corpus spans multiple subsets, the figure is the whole collection.

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