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Dataset specification · Flagship scale

2,000 hours of Hinglish Spontaneous Speech

A flagship scale build of 2,000 hours of Hinglish 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.

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Structured dataset packages ready for delivery — 2,000 hours of Hinglish Spontaneous Speech
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
01

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.

Flagship scale — what the build is actually made ofCitiesTwelve or more, includi…StudiosFourteen rooms plus six…RecruitersSixteen coordinators, t…Speakers~4,000–5,000Sessions per day120–150 nationallyTeam1 programme director, 3…
02

The specification

FieldValue
LanguageHinglish (hi-Latn-IN, Devanagari + Latin)
Volume2,000 hours
Equivalent4,000 speakers at 30 minutes each, or 2,000 speakers at one hour each
Speech typeSpontaneous Speech
Per speaker25–40 minutes of accepted audio per speaker
File granularitySession-length WAV plus segmented utterance files with offsets into the parent
SegmentationPause-boundary segmentation, reviewed by a native listener rather than left to VAD
Moderator channelRecorded separately and excluded from the delivered speaker audio
Disfluency conventionFilled pauses, repetitions and false starts transcribed, not normalised away
DialectsDelhi corporate Hinglish, Mumbai Bambaiya, Call-centre register, Youth/social media register
TranscriptionVerbatim, native-speaker, second-pass reviewed
Speaker reading a prompt script into a studio microphone — supporting 2,000 hours of hinglish spontaneous speech
Speaker reading a prompt script into a studio microphone
03

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.
04

Running a flagship scale Hinglish 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.

Recruit by switching behaviour, not by language proficiency. Screening recordings are used to confirm speakers switch naturally rather than performing one language.

ParameterAt this volume
CitiesTwelve or more, including tier-2 and rural catchments — Delhi, Gurugram, Noida, Mumbai, Bengaluru, Pune, Hyderabad
StudiosFourteen rooms plus six mobile rigs
RecruitersSixteen coordinators, three regional managers, one programme director
Speakers~4,000–5,000
Sessions per day120–150 nationally
Team1 programme director, 3 regional managers, 16 coordinators, 30 engineers, 80 transcribers, 8 QA leads
05

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.

DimensionTypical splitWhy it matters for Hinglish
Gender50 / 50Pitch range differences change acoustic model behaviour; unbalanced cohorts bias recognition
Age18-25: 30%, 26-40: 40%, 41-60: 30%Older speakers retain conservative Hinglish forms that younger urban speakers have lost
RegionDelhi NCR / Mumbai / Bengaluru and othersDialect spread across 4 recognised varieties
EducationMixed, including below-graduatePrompt-reading fluency correlates with education and skews prosody
ConditionStudio / quiet room / fieldMatch the noise profile of your deployment
06

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.
07

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, 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.

08

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
09

Risks at flagship scale in Hinglish

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
  • 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.
10

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
11

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 Hinglish 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 Hinglish 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 Hinglish 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 Hinglish dataset

2,000 hours, spontaneous speech, Hinglish — flagship scale. Adjust anything and send it.

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