Dataset specification · Flagship scale
2,000 hours of Telugu Spontaneous Speech
A flagship scale build of 2,000 hours of Telugu 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 Telugu 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 | Telugu (te-IN, Telugu) |
| 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 | Telangana, Coastal Andhra (Godavari), Rayalaseema, Srikakulam |
| Transcription | Verbatim, native-speaker, second-pass reviewed |

Designing the topic bank for Telugu
- 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 Telugu specifically: Vowel-length contrasts are phonemic and short/long confusion changes meaning outright
- Code-mixing handled explicitly rather than edited out — Hyderabad speech mixes Telugu, Urdu/Deccani, Hindi and English. A Telugu dataset for Hyderabad deployment must include Urdu-origin vocabulary.
Running a flagship scale Telugu 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.
Split cohorts explicitly between Telangana and Andhra Pradesh and tag every speaker; models trained without the tag cannot be evaluated per region.
| Parameter | At this volume |
|---|---|
| Cities | Twelve or more, including tier-2 and rural catchments — Hyderabad, Vijayawada, Visakhapatnam, Warangal, Tirupati |
| 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 Telugu |
|---|---|---|
| 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 Telugu forms that younger urban speakers have lost |
| Region | Andhra Pradesh / Telangana / parts of Karnataka and Odisha and others | Dialect spread across 4 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 |
Telugu-specific considerations
- Vowel-length contrasts are phonemic and short/long confusion changes meaning outright
- Hyderabad speech mixes Telugu, Urdu/Deccani, Hindi and English. A Telugu dataset for Hyderabad deployment must include Urdu-origin vocabulary.
- Coastal Andhra read speech dominates. Telangana rural and Rayalaseema speech is thin, despite Hyderabad being the largest deployment market.
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
- Telangana forms normalised to Coastal Andhra standard
- Long/short vowel marking errors under time pressure
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 Telugu
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
- Telugu carries 4 recognised varieties across Andhra Pradesh, Telangana, parts of Karnataka and Odisha, so the quota matrix is wider than the headline volume suggests
- Coastal Andhra read speech dominates. Telangana rural and Rayalaseema speech is thin, despite Hyderabad being the largest deployment market.
Deliverables
- WAV audio to your naming convention, with the per-file manifest
- Verbatim Telugu 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 Telugu 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 Telugu 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 Telugu 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 Telugu dataset
2,000 hours, spontaneous speech, Telugu — flagship scale. Adjust anything and send it.