Dataset specification · Production scale
500 hours of Hinglish Conversational Speech
A production scale build of 500 hours of Hinglish conversational speech. The point at which a corpus is large enough to train a deployable model rather than adapt someone else's. Two speakers hold an unscripted conversation seeded with a scenario, recorded on separate channels so overlap and turn-taking survive into the delivered files.

- Volume
- 500 hours
- Scale
- Production scale
- Per speaker
- 20–30 minutes of accepted audio per speaker, in pairs
- Accepted yield
- 55–65% of recorded time is accepted
How Hinglish conversational speech is captured
Two speakers hold an unscripted conversation seeded with a scenario, recorded on separate channels so overlap and turn-taking survive into the delivered files.
A 45–60 minute paired session with both speakers on isolated microphones, either in adjacent treated rooms or split-mic in one room with bleed measured and logged.
Yield at this style: 55–65% of recorded time is accepted. Overlap regions, crosstalk bleed and one-sided stretches all cost delivered time. The lowest-yield studio style we run, and priced accordingly.
The specification
| Field | Value |
|---|---|
| Language | Hinglish (hi-Latn-IN, Devanagari + Latin) |
| Volume | 500 hours |
| Equivalent | 1,000 speakers at 30 minutes each, or 500 speakers at one hour each |
| Speech type | Conversational Speech |
| Per speaker | 20–30 minutes of accepted audio per speaker, in pairs |
| Channels | Two, one per speaker, never mixed down before delivery |
| Channel isolation | Bleed measured per session and logged; sessions over threshold are re-recorded |
| Overlap | Preserved, timestamped and labelled rather than edited out |
| File granularity | Per-channel session WAV plus a turn-level manifest with speaker IDs |
| Dialects | Delhi corporate Hinglish, Mumbai Bambaiya, Call-centre register, Youth/social media register |
| Transcription | Verbatim, native-speaker, second-pass reviewed |

Designing the scenarios for Hinglish
- Scenario seeds rather than scripts — a disagreement to resolve, a plan to make, an experience to compare
- Pairing designed deliberately: familiar pairs produce natural interruption, stranger pairs produce polite turn-taking, and you need both
- Scenarios that invite disagreement, because agreeable conversation produces almost no overlap to train on
- Register mixed across pairs so the corpus is not uniformly formal
- 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 production scale Hinglish 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.
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 | Five to six — Delhi, Gurugram, Noida, Mumbai, Bengaluru |
| 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.
Effectively doubles recruitment load, since speakers are booked in matched pairs and a single drop-out cancels the whole session. Plan on 20–25% over-recruitment.
| 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 conversational speech
- Channel bleed measured on every session and rejected above the agreed threshold
- Diarisation labels verified against the isolated channels rather than inferred from the mix
- Turn boundaries and overlap regions checked by a native listener
- Speaking-time balance per pair audited, so a dominant speaker does not silently halve the session's value
- 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, 10% content QA stratified by city, dialect, transcriber and recording condition, with automatic escalation to 100% on any failing batch.
What goes wrong on conversational speech sessions
- Crosstalk bleed that makes clean per-speaker training targets impossible to recover afterwards
- One speaker dominating, leaving a pair that delivers half the expected audio
- Unnatural politeness between strangers, producing clean but unrepresentative turn-taking
- Scheduling attrition — both speakers have to show up, so no-show rates compound rather than add
Risks at production scale in Hinglish
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
- 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
- Speaker-turn segmentation with start and end timestamps
- Overlap regions marked with participating speaker IDs
- Backchannel and interruption markers
- Per-pair relationship metadata: familiar or stranger
- 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
- Speaker diarisation
- Meeting and multi-party ASR
- Turn-taking and endpointing for voice agents
- Speaker separation and target-speaker extraction
Two-party conversation does not generalise to multi-party meetings with four or more speakers, where overlap statistics change substantially. Specify that case separately.
Frequently asked
Is 500 hours of Hinglish 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 conversational speech rather than another speech type?
Speaker diarisation, Meeting and multi-party ASR, Turn-taking and endpointing for voice agents are what this style is the right input for. Two-party conversation does not generalise to multi-party meetings with four or more speakers, where overlap statistics change substantially. Specify that case separately.
How long does a production scale Hinglish 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 Hinglish conversational 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 Hinglish dataset
500 hours, conversational speech, Hinglish — production scale. Adjust anything and send it.