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Dataset specification · Pilot cohort

100 speakers of Hindi Conversational Speech

A pilot cohort build of 100 speakers of Hindi conversational speech. Establishing whether a cohort definition is recruitable at all before it is scaled. Two speakers hold an unscripted conversation seeded with a scenario, recorded on separate channels so overlap and turn-taking survive into the delivered files.

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Two speakers recording natural conversational speech data — 100 speakers of Hindi Conversational Speech
Volume
100 speakers
Scale
Pilot cohort
Per speaker
20–30 minutes of accepted audio per speaker, in pairs
Accepted yield
55–65% of recorded time is accepted
01

How Hindi 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.

Pilot cohort — what the build is actually made ofCitiesOneStudiosA single treated roomRecruitersOne coordinatorAudio yield~50 hours at 30 minutes…Sessions per day6–8Team1 coordinator, 2 engine…
02

The specification

FieldValue
LanguageHindi (hi-IN, Devanagari)
Volume100 speakers
Equivalent50 hours at 30 minutes per speaker
Speech typeConversational Speech
Per speaker20–30 minutes of accepted audio per speaker, in pairs
ChannelsTwo, one per speaker, never mixed down before delivery
Channel isolationBleed measured per session and logged; sessions over threshold are re-recorded
OverlapPreserved, timestamped and labelled rather than edited out
File granularityPer-channel session WAV plus a turn-level manifest with speaker IDs
DialectsKhari Boli, Awadhi, Braj, Bhojpuri-influenced Hindi
TranscriptionVerbatim, native-speaker, second-pass reviewed
Structured dataset packages ready for delivery — supporting 100 speakers of hindi conversational speech
Structured dataset packages ready for delivery
03

Designing the scenarios for Hindi

  • 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 Hindi specifically: Four-way stop contrast (voiced/voiceless x aspirated/unaspirated) that collapses in models trained on English-first acoustic units
  • Code-mixing handled explicitly rather than edited out — Urban Hindi speech is Hinglish in practice. Expect 15-40% English tokens in spontaneous speech: numbers, brands, technology terms, and whole clause switches. Any Hindi corpus that excludes English tokens will not match production traffic.
04

Running a pilot cohort Hindi build

Three to four weeks, almost entirely determined by how narrow the screening criteria are.

A single delivery with the full demographic report, since the cohort report is the point of a build this size.

Largest recruitment pool in the network. A 1,000-speaker Hindi cohort with balanced gender and 18-45 age bands is typically fielded across four cities to avoid a single-city accent bias.

ParameterAt this volume
CitiesOne — Delhi, Lucknow
StudiosA single treated room
RecruitersOne coordinator
Audio yield~50 hours at 30 minutes per speaker
Sessions per day6–8
Team1 coordinator, 2 engineers, 3 transcribers
05

Cohort design

At 100 speakers 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.

DimensionTypical splitWhy it matters for Hindi
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 Hindi forms that younger urban speakers have lost
RegionUttar Pradesh / Bihar / Madhya Pradesh and othersDialect spread across 7 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

Hindi-specific considerations

  • Four-way stop contrast (voiced/voiceless x aspirated/unaspirated) that collapses in models trained on English-first acoustic units
  • Urban Hindi speech is Hinglish in practice. Expect 15-40% English tokens in spontaneous speech: numbers, brands, technology terms, and whole clause switches. Any Hindi corpus that excludes English tokens will not match production traffic.
  • Public Hindi corpora skew heavily towards read newspaper text from educated urban speakers in Delhi and NCR. Rural Bihar and eastern UP speech, elderly speakers, and low-literacy speakers reading prompts aloud are largely absent.
07

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
  • Inconsistent Devanagari vs romanised spelling for the same English loan word
  • Nukta characters (क़ ख़ ग़ ज़ फ़) applied inconsistently by transcribers

100% content QA, plus per-speaker demographic verification against the screening record.

08

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
09

Risks at pilot cohort in Hindi

Cost at this band is driven by: Screening narrowness dominates; the recording itself is a minor cost at this size.

  • Narrow criteria can make a cohort unrecruitable at any price, which is exactly what this band exists to find out
  • 100 speakers cannot support per-dialect evaluation — treat the results as directional
  • Hindi carries 7 recognised varieties across Uttar Pradesh, Bihar, Madhya Pradesh, so the quota matrix is wider than the headline volume suggests
  • Public Hindi corpora skew heavily towards read newspaper text from educated urban speakers in Delhi and NCR. Rural Bihar and eastern UP speech, elderly speakers, and low-literacy speakers reading prompts aloud are largely absent.
10

Deliverables

  • WAV audio to your naming convention, with the per-file manifest
  • Verbatim Devanagari 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
11

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 speakers of Hindi enough?

Enough to prove a cohort definition works and to build a small speaker-verification or accent test set. Not enough for per-dialect statistics.

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 pilot cohort Hindi build take?

Three to four weeks, almost entirely determined by how narrow the screening criteria are. A single delivery with the full demographic report, since the cohort report is the point of a build this size.

What does 100 speakers of Hindi conversational speech cost?

Quoted per delivered hour against this specification. At this band the drivers are screening narrowness dominates; the recording itself is a minor cost at this size. Send the spec and you get one fixed figure.

How much QA is applied at this volume?

100% content QA, plus per-speaker demographic verification against the screening record.

Quote this Hindi dataset

100 speakers, conversational speech, Hindi — pilot cohort. Adjust anything and send it.

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