Dataset specification · Production cohort
1,000 speakers of Gujarati Scripted Speech
A production cohort build of 1,000 speakers of Gujarati scripted speech. Generalisation across speakers, which is what actually drives real-world ASR robustness. Speakers read prompts from a phonetically balanced script shown one line at a time, with retakes on any flubbed or misread line.

- Volume
- 1,000 speakers
- Scale
- Production cohort
- Per speaker
- 20–30 minutes of accepted audio per speaker
- Accepted yield
- 85–90% of recorded time is accepted
How Gujarati scripted speech is captured
Speakers read prompts from a phonetically balanced script shown one line at a time, with retakes on any flubbed or misread line.
A 45-minute booth session yields roughly 300–400 prompts. One file per utterance, cut at the prompt boundary, so alignment is exact before any forced-alignment pass runs.
Yield at this style: 85–90% of recorded time is accepted. Prompt-level retakes catch problems inside the session, so very little is discarded afterwards. This is the highest-yield style we run.
The specification
| Field | Value |
|---|---|
| Language | Gujarati (gu-IN, Gujarati) |
| Volume | 1,000 speakers |
| Equivalent | 500 hours at 30 minutes per speaker |
| Speech type | Scripted Speech |
| Per speaker | 20–30 minutes of accepted audio per speaker |
| File granularity | One WAV per prompt, named by prompt ID and speaker ID |
| Prompt coverage | Triphone-balanced script with digit, date, name and domain-lexicon blocks |
| Leading/trailing silence | 200 ms padded, verified automatically on every file |
| Alignment | Prompt text is ground truth; deviations are flagged rather than silently corrected |
| Dialects | Standard (Amdavadi), Surti, Kathiyawadi, Kachchhi-influenced |
| Transcription | Verbatim, native-speaker, second-pass reviewed |

Designing the script for Gujarati
- Script built for triphone coverage rather than word coverage, so rare phone contexts appear often enough to train on
- Digit strings, dates, currency and person names blocked separately, because these are where deployed ASR actually fails
- Domain lexicon injected from your product vocabulary when you supply one
- Sentence-length distribution spread deliberately, since all-short prompts produce a model that cannot handle long utterances
- 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 production cohort Gujarati build
Nine to twelve weeks, with recruitment running continuously rather than in a front-loaded phase.
Six to eight batches, speaker-disjoint by construction so held-out speakers are genuinely held out.
Surat and Rajkot recruitment is essential for dialect coverage; Ahmedabad-only cohorts sound uniform.
| Parameter | At this volume |
|---|---|
| Cities | Six to eight — Ahmedabad, Surat, Vadodara, Rajkot, Bhavnagar |
| Studios | Eight rooms plus two mobile rigs |
| Recruiters | Eight coordinators, one regional manager |
| Audio yield | ~500 hours at 30 minutes per speaker |
| Sessions per day | 45–55 |
| Team | 1 programme lead, 1 regional manager, 8 coordinators, 14 engineers, 25 transcribers, 3 QA leads |
Cohort design
At 1,000 speakers 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.
Requires literate speakers comfortable reading aloud in the target script, which is the main constraint on cohort breadth and has to be actively counterweighted.
| 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 scripted speech
- Prompt-to-audio match verified by a native reviewer; a misread line is a rejected file, not an edited transcript
- Hyperarticulation flagged — a speaker over-enunciating because they are reading produces audio that does not match deployment
- Clipping and truncation checked at both utterance boundaries
- Per-speaker prompt coverage confirmed, so no speaker silently skips a block
- Breathy vowels have no consistent orthographic marking
- Kathiyawadi lexical items replaced with standard equivalents
100% technical QA, 10% content QA stratified by city and coordinator, with voice-based duplicate detection across the whole cohort.
What goes wrong on scripted speech sessions
- Reading voice: flat prosody and unnatural stress that trains a model on speech nobody actually produces
- Prompt fatigue in the back half of long sessions, where accuracy drops and pace flattens
- Speakers who are not fluent readers, which quietly biases the cohort toward higher education bands
- Script leakage across speakers, producing a corpus that memorises sentences instead of covering sounds
Risks at production cohort in Gujarati
Cost at this band is driven by: Number of distinct demographic cells rather than total speakers.
- Speaker-disjoint splits are only trustworthy if duplicate detection is voice-based rather than ID-based, since one person can present two identities
- Coordinator-level demographic bias becomes measurable at this size and should be reported, not smoothed over
- 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
- Prompt ID mapped to every utterance
- Verbatim deviation flags where the speaker departed from the script
- Per-utterance SNR and duration in the manifest
- 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
- ASR acoustic model baselines
- TTS voice building where a single speaker is recorded at depth
- Pronunciation lexicon and G2P validation
- Forced-alignment and phone-boundary work
Scripted audio contains no disfluencies, no false starts and no natural turn-taking. A model trained on it alone degrades sharply on real spontaneous input, so it is a baseline layer rather than a complete training set.
Frequently asked
Is 1,000 speakers of Gujarati enough?
Enough for production ASR generalisation and for a speaker-verification corpus with meaningful negative pairs.
Why scripted speech rather than another speech type?
ASR acoustic model baselines, TTS voice building where a single speaker is recorded at depth, Pronunciation lexicon and G2P validation are what this style is the right input for. Scripted audio contains no disfluencies, no false starts and no natural turn-taking. A model trained on it alone degrades sharply on real spontaneous input, so it is a baseline layer rather than a complete training set.
How long does a production cohort Gujarati build take?
Nine to twelve weeks, with recruitment running continuously rather than in a front-loaded phase. Six to eight batches, speaker-disjoint by construction so held-out speakers are genuinely held out.
What does 1,000 speakers of Gujarati scripted speech cost?
Quoted per delivered hour against this specification. At this band the drivers are number of distinct demographic cells rather than total speakers. Send the spec and you get one fixed figure.
How much QA is applied at this volume?
100% technical QA, 10% content QA stratified by city and coordinator, with voice-based duplicate detection across the whole cohort.
Quote this Gujarati dataset
1,000 speakers, scripted speech, Gujarati — production cohort. Adjust anything and send it.