Dataset specification · Flagship cohort
2,000 speakers of Hinglish Spontaneous Speech
A flagship cohort build of 2,000 speakers of Hinglish spontaneous speech. Maximum speaker diversity, for foundation work or a reference corpus where per-cell statistics must hold. 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 speakers
- Scale
- Flagship cohort
- Per speaker
- 25–40 minutes of accepted audio per speaker
- Accepted yield
- 60–70% of recorded time is accepted
How Hinglish 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 | Hinglish (hi-Latn-IN, Devanagari + Latin) |
| Volume | 2,000 speakers |
| Equivalent | 1,000 hours at 30 minutes per speaker |
| 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 | Delhi corporate Hinglish, Mumbai Bambaiya, Call-centre register, Youth/social media register |
| Transcription | Verbatim, native-speaker, second-pass reviewed |

Designing the topic bank for Hinglish
- 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 Hinglish specifically: Intra-sentential switching means English words carry Indian phonology, so English acoustic models mis-transcribe them
- Code-mixing handled explicitly rather than edited out — Hinglish is the code-mixing case itself. Typical urban customer-support speech is 30-60% English tokens embedded in Hindi grammar, with switching several times per utterance.
Running a flagship cohort Hinglish build
Sixteen to twenty-two weeks, run in waves so that recruitment in the harder catchments starts early rather than being left to the end.
Ten to twelve batches with rolling demographic reconciliation, since a quota gap discovered in week eighteen is very expensive to close.
Recruit by switching behaviour, not by language proficiency. Screening recordings are used to confirm speakers switch naturally rather than performing one language.
| Parameter | At this volume |
|---|---|
| Cities | Twelve or more, including rural catchments — Delhi, Gurugram, Noida, Mumbai, Bengaluru, Pune, Hyderabad |
| Studios | Twelve rooms plus five mobile rigs |
| Recruiters | Fourteen coordinators, three regional managers, one programme director |
| Audio yield | ~1,000 hours at 30 minutes per speaker |
| Sessions per day | 90–110 |
| Team | 1 programme director, 3 regional managers, 14 coordinators, 24 engineers, 45 transcribers, 6 QA leads |
Cohort design
At 2,000 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.
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 Hinglish |
|---|---|---|
| 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 Hinglish forms that younger urban speakers have lost |
| Region | Delhi NCR / Mumbai / Bengaluru 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 |
Hinglish-specific considerations
- Intra-sentential switching means English words carry Indian phonology, so English acoustic models mis-transcribe them
- Hinglish is the code-mixing case itself. Typical urban customer-support speech is 30-60% English tokens embedded in Hindi grammar, with switching several times per utterance.
- Almost no public corpus contains genuine intra-sentential Hindi-English switching with per-token language tags. This is the highest-value gap for anyone building Indian conversational AI.
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
- Whether English tokens are written in Latin or transliterated into Devanagari must be fixed by rule, not left to annotators
- Language-ID tagging per token is required for training but is skipped by most vendors
100% technical QA, 7% content QA stratified across every axis, blind re-transcription audit, and per-cell demographic sign-off before final acceptance.
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 cohort in Hinglish
Cost at this band is driven by: Long-tail demographic cells, which dominate both cost and schedule at this size.
- The final 15% of the cohort — the rarest demographic cells — routinely takes as long as the first half and should be scheduled first, not last
- Speaker pool exhaustion is a hard constraint in all but the largest languages
- Voice-based duplicate detection across 2,000 speakers is a genuine engineering task, not a spreadsheet check
- Hinglish carries 4 recognised varieties across Delhi NCR, Mumbai, Bengaluru, so the quota matrix is wider than the headline volume suggests
- Almost no public corpus contains genuine intra-sentential Hindi-English switching with per-token language tags. This is the highest-value gap for anyone building Indian conversational AI.
Deliverables
- WAV audio to your naming convention, with the per-file manifest
- Verbatim Devanagari + Latin 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 speakers of Hinglish enough?
Enough for foundation-scale speaker diversity and for a reference cohort with statistically meaningful per-dialect and per-demographic cells.
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 cohort Hinglish build take?
Sixteen to twenty-two weeks, run in waves so that recruitment in the harder catchments starts early rather than being left to the end. Ten to twelve batches with rolling demographic reconciliation, since a quota gap discovered in week eighteen is very expensive to close.
What does 2,000 speakers of Hinglish spontaneous speech cost?
Quoted per delivered hour against this specification. At this band the drivers are long-tail demographic cells, which dominate both cost and schedule at this size. Send the spec and you get one fixed figure.
How much QA is applied at this volume?
100% technical QA, 7% content QA stratified across every axis, blind re-transcription audit, and per-cell demographic sign-off before final acceptance.
Quote this Hinglish dataset
2,000 speakers, spontaneous speech, Hinglish — flagship cohort. Adjust anything and send it.