Dataset specification · Flagship scale
2,000 hours of Gujarati Spontaneous Speech
A flagship scale build of 2,000 hours of Gujarati spontaneous speech. Foundation-model input, or a multi-year corpus intended to be the reference dataset for a language. Speakers talk unscripted on prompted topics — describing a process, recounting an event, arguing a position — with a moderator who prompts but does not lead.

- Volume
- 2,000 hours
- Scale
- Flagship scale
- Per speaker
- 25–40 minutes of accepted audio per speaker
- Accepted yield
- 60–70% of recorded time is accepted
How Gujarati spontaneous speech is captured
Speakers talk unscripted on prompted topics — describing a process, recounting an event, arguing a position — with a moderator who prompts but does not lead.
A 60-minute session covering six to eight topics, recorded continuously and segmented afterwards into utterances at natural pause boundaries.
Yield at this style: 60–70% of recorded time is accepted. Long silences, moderator speech and abandoned topics are cut in post, so recorded hours run well ahead of delivered hours. Budget for the gap.
The specification
| Field | Value |
|---|---|
| Language | Gujarati (gu-IN, Gujarati) |
| Volume | 2,000 hours |
| Equivalent | 4,000 speakers at 30 minutes each, or 2,000 speakers at one hour each |
| Speech type | Spontaneous Speech |
| Per speaker | 25–40 minutes of accepted audio per speaker |
| File granularity | Session-length WAV plus segmented utterance files with offsets into the parent |
| Segmentation | Pause-boundary segmentation, reviewed by a native listener rather than left to VAD |
| Moderator channel | Recorded separately and excluded from the delivered speaker audio |
| Disfluency convention | Filled pauses, repetitions and false starts transcribed, not normalised away |
| Dialects | Standard (Amdavadi), Surti, Kathiyawadi, Kachchhi-influenced |
| Transcription | Verbatim, native-speaker, second-pass reviewed |

Designing the topic bank for Gujarati
- Topic banks graded by familiarity, so speakers across education and occupation bands all have something to say
- Open prompts only — anything answerable with yes or no produces thirty seconds of audio and a stalled session
- Culturally grounded topics per region, since a prompt that works in Mumbai can draw blank looks in Guwahati
- Topic rotation across the cohort so the corpus does not over-represent a handful of subjects
- Built against Gujarati specifically: Murmured (breathy-voiced) vowels are phonemic in Gujarati and are absent from most shared Indic acoustic models
- Code-mixing handled explicitly rather than edited out — Business and trade vocabulary is heavily English; Gujarati diaspora speech adds further English structure. Specify whether diaspora speakers are in or out of scope.
Running a flagship scale Gujarati build
Twenty to twenty-eight weeks, run in two or three waves. Wave one establishes the protocol and the transcription convention; later waves scale against a proven baseline rather than an assumed one.
Continuous fortnightly delivery from week four, roughly fourteen batches, each with acceptance testing and a rolling demographic reconciliation against the target quota matrix.
Surat and Rajkot recruitment is essential for dialect coverage; Ahmedabad-only cohorts sound uniform.
| Parameter | At this volume |
|---|---|
| Cities | Twelve or more, including tier-2 and rural catchments — Ahmedabad, Surat, Vadodara, Rajkot, Bhavnagar |
| Studios | Fourteen rooms plus six mobile rigs |
| Recruiters | Sixteen coordinators, three regional managers, one programme director |
| Speakers | ~4,000–5,000 |
| Sessions per day | 120–150 nationally |
| Team | 1 programme director, 3 regional managers, 16 coordinators, 30 engineers, 80 transcribers, 8 QA leads |
Cohort design
At 2,000 hours the quota matrix is enforced per cell, not in aggregate. Every dialect, age and gender combination carries its own target and is signed off individually before final acceptance, because an aggregate 50/50 split can hide a cell that was never filled at all.
Screening is for willingness to talk, not literacy, which opens the cohort to speakers a scripted protocol would exclude. Expect to over-recruit by 15% for speakers who freeze on the day.
| Dimension | Typical split | Why it matters for Gujarati |
|---|---|---|
| Gender | 50 / 50 | Pitch range differences change acoustic model behaviour; unbalanced cohorts bias recognition |
| Age | 18-25: 30%, 26-40: 40%, 41-60: 30% | Older speakers retain conservative Gujarati forms that younger urban speakers have lost |
| Region | Gujarat / Daman & Diu / Dadra & Nagar Haveli and others | Dialect spread across 5 recognised varieties |
| Education | Mixed, including below-graduate | Prompt-reading fluency correlates with education and skews prosody |
| Condition | Studio / quiet room / field | Match the noise profile of your deployment |
Gujarati-specific considerations
- Murmured (breathy-voiced) vowels are phonemic in Gujarati and are absent from most shared Indic acoustic models
- Business and trade vocabulary is heavily English; Gujarati diaspora speech adds further English structure. Specify whether diaspora speakers are in or out of scope.
- Very little spontaneous Gujarati audio exists publicly; nearly all of it is Ahmedabad read speech.
Quality gates for spontaneous speech
- Segment boundary review — bad boundaries produce truncated words that poison training more than they help
- Disfluency transcription consistency audited across transcribers, since conventions drift fast on this style
- Moderator speech confirmed absent from delivered segments
- Topic distribution checked per speaker so one dominant subject does not skew the language model
- Breathy vowels have no consistent orthographic marking
- Kathiyawadi lexical items replaced with standard equivalents
100% technical QA, 5% content QA stratified across every axis, a blind 2% re-transcription audit, and a monthly cross-wave consistency review comparing early and late batches for drift.
What goes wrong on spontaneous speech sessions
- Speakers who dry up after a minute, leaving sessions that look complete by duration but are mostly silence
- Drift into a reading register when a speaker becomes self-conscious about the microphone
- Moderator over-prompting, which turns a monologue corpus into an interview corpus
- Transcriber normalisation — quietly cleaning up disfluencies destroys the exact signal this style exists to capture
Risks at flagship scale in Gujarati
Cost at this band is driven by: Wave structure and the programme governance it requires; Long-tail demographic and dialect quotas, which dominate the final third of the build.
- Drift between waves is the defining risk: audio recorded in month one and month six must be indistinguishable in convention, or the corpus splits into two datasets
- Speaker pool exhaustion is a live constraint in all but the largest languages and shapes which cities are used
- Staff turnover across twenty-eight weeks is a certainty, so handover documentation is part of the deliverable rather than an afterthought
- Storage, transfer and manifest integrity become engineering problems in their own right at this size
- Gujarati carries 5 recognised varieties across Gujarat, Daman & Diu, Dadra & Nagar Haveli, so the quota matrix is wider than the headline volume suggests
- Very little spontaneous Gujarati audio exists publicly; nearly all of it is Ahmedabad read speech.
Deliverables
- WAV audio to your naming convention, with the per-file manifest
- Verbatim Gujarati transcripts with utterance-level timestamps
- Filled-pause and false-start markers
- Segment offsets into the parent session file
- Topic label per segment
- Speech-rate and pause-density statistics per speaker
- Per-speaker metadata: age band, gender, region, dialect, education band
- Consent records mapped to speaker IDs
- QA report with pass rates, rejection reasons and agreement statistics
- Speaker-disjoint train / dev / test splits on request
What this trains, and what it does not
- Robust ASR for real user speech
- Language modelling on natural syntax
- Disfluency detection and removal
- Prosody and speech-rate modelling
Phonetic balance cannot be guaranteed — speakers say what they say. If you need specific phone contexts or a controlled lexicon, this style has to be paired with a scripted layer.
Frequently asked
Is 2,000 hours of Gujarati enough?
Enough for foundation-model pre-training input in one language, or a reference corpus intended to outlive the model that prompted it.
Why spontaneous speech rather than another speech type?
Robust ASR for real user speech, Language modelling on natural syntax, Disfluency detection and removal are what this style is the right input for. Phonetic balance cannot be guaranteed — speakers say what they say. If you need specific phone contexts or a controlled lexicon, this style has to be paired with a scripted layer.
How long does a flagship scale Gujarati build take?
Twenty to twenty-eight weeks, run in two or three waves. Wave one establishes the protocol and the transcription convention; later waves scale against a proven baseline rather than an assumed one. Continuous fortnightly delivery from week four, roughly fourteen batches, each with acceptance testing and a rolling demographic reconciliation against the target quota matrix.
What does 2,000 hours of Gujarati spontaneous speech cost?
Quoted per delivered hour against this specification. At this band the drivers are wave structure and the programme governance it requires and long-tail demographic and dialect quotas, which dominate the final third of the build. Send the spec and you get one fixed figure.
How much QA is applied at this volume?
100% technical QA, 5% content QA stratified across every axis, a blind 2% re-transcription audit, and a monthly cross-wave consistency review comparing early and late batches for drift.
Quote this Gujarati dataset
2,000 hours, spontaneous speech, Gujarati — flagship scale. Adjust anything and send it.