Dataset specification · Evaluation scale
100 hours of Hinglish Conversational Speech
An evaluation scale build of 100 hours of Hinglish conversational speech. Building a benchmark or evaluation set that is large enough to trust, or fine-tuning a narrow domain. 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
- 100 hours
- Scale
- Evaluation 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 | 100 hours |
| Equivalent | 200 speakers at 30 minutes each, or 100 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 an evaluation scale Hinglish build
Four to six weeks. Two cities running in parallel means recruitment and recording overlap rather than queue behind each other.
Three batches at roughly two-week intervals, each one a self-contained, speaker-disjoint slice you can evaluate independently.
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 | Two, chosen for dialect contrast — Delhi, Gurugram |
| Studios | Two rooms running in parallel |
| Recruiters | Two coordinators |
| Speakers | ~200–240 |
| Sessions per day | 12–16 across both cities |
| Team | 2 coordinators, 4 engineers, 6 transcribers, 1 QA lead |
Cohort design
At 100 hours the cohort is deliberately simplified: two or three dialect groups rather than the full spread, with quotas enforced in aggregate. A build this size cannot support per-cell targets and should not claim to.
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, 25% content QA, escalating to full review on any batch that fails the agreed error threshold.
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 evaluation scale in Hinglish
Cost at this band is driven by: Dialect spread is the main driver at this band — two contrasting cities cost more than two convenient ones; Turnaround compression, if you need it inside four weeks.
- Two-city cohorts can hide a dialect gap that only appears when the model meets a third region
- Transcription consistency between two city teams needs an explicit convention document or the batches will not match
- 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 100 hours of Hinglish enough?
A solid evaluation set, and enough to fine-tune an existing multilingual model on a narrow domain. Still short of what a general production model needs.
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 an evaluation scale Hinglish build take?
Four to six weeks. Two cities running in parallel means recruitment and recording overlap rather than queue behind each other. Three batches at roughly two-week intervals, each one a self-contained, speaker-disjoint slice you can evaluate independently.
What does 100 hours of Hinglish conversational speech cost?
Quoted per delivered hour against this specification. At this band the drivers are dialect spread is the main driver at this band — two contrasting cities cost more than two convenient ones and turnaround compression, if you need it inside four weeks. Send the spec and you get one fixed figure.
How much QA is applied at this volume?
100% technical QA, 25% content QA, escalating to full review on any batch that fails the agreed error threshold.
Quote this Hinglish dataset
100 hours, conversational speech, Hinglish — evaluation scale. Adjust anything and send it.