Dataset specification · Production scale
500 hours of Gujarati Scripted Speech
A production scale build of 500 hours of Gujarati scripted speech. The point at which a corpus is large enough to train a deployable model rather than adapt someone else's. Speakers read prompts from a phonetically balanced script shown one line at a time, with retakes on any flubbed or misread line.

- Volume
- 500 hours
- Scale
- Production scale
- 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 | 500 hours |
| Equivalent | 1,000 speakers at 30 minutes each, or 500 speakers at one hour each |
| 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 scale Gujarati build
Eight to twelve weeks. Cities are staggered rather than started together, so the protocol corrections found in the first city are applied before the last one begins recording.
Six to eight batches, fortnightly, each speaker-disjoint so you can train on early batches without contaminating a later evaluation split.
Surat and Rajkot recruitment is essential for dialect coverage; Ahmedabad-only cohorts sound uniform.
| Parameter | At this volume |
|---|---|
| Cities | Five to six — Ahmedabad, Surat, Vadodara, Rajkot, Bhavnagar |
| Studios | Six rooms plus two mobile rigs for rural capture |
| Recruiters | Six coordinators under one programme lead |
| Speakers | ~1,000–1,200 |
| Sessions per day | 40–50 nationally |
| Team | 1 programme lead, 6 coordinators, 12 engineers, 25 transcribers, 3 QA leads |
Cohort design
At 500 hours quotas are enforced per dialect and reconciled fortnightly. Aggregate demographics are reported per batch so drift is visible while there is still time to correct it.
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, dialect, transcriber and recording condition, with automatic escalation to 100% on any failing batch.
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 scale in Gujarati
Cost at this band is driven by: Field and rural capture ratio — mobile rig hours cost more than studio hours; Rare dialect quotas, where the last 10% of the cohort can cost as much as the first 40%.
- Speaker duplication across cities becomes a real risk at this cohort size and needs active de-duplication against voice and ID
- Rural capture depends on weather and travel in a way studio work does not, so mobile-rig batches carry schedule variance
- Quota drift compounds across six cities unless demographics are reconciled weekly rather than at the end
- 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 500 hours of Gujarati enough?
Enough to train a deployable model for a single language, or to substantially improve a multilingual one. This is the most common production band.
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 scale Gujarati build take?
Eight to twelve weeks. Cities are staggered rather than started together, so the protocol corrections found in the first city are applied before the last one begins recording. Six to eight batches, fortnightly, each speaker-disjoint so you can train on early batches without contaminating a later evaluation split.
What does 500 hours of Gujarati scripted speech cost?
Quoted per delivered hour against this specification. At this band the drivers are field and rural capture ratio — mobile rig hours cost more than studio hours and rare dialect quotas, where the last 10% of the cohort can cost as much as the first 40%. 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, dialect, transcriber and recording condition, with automatic escalation to 100% on any failing batch.
Quote this Gujarati dataset
500 hours, scripted speech, Gujarati — production scale. Adjust anything and send it.