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Dataset specification · Pilot cohort

100 speakers of Indian English Conversational Speech

A pilot cohort build of 100 speakers of Indian English 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 Indian English 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 Indian English 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
LanguageIndian English (en-IN, Latin)
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
DialectsNorth Indian (Hindi-substrate), Maharashtrian, South Indian (Tamil/Telugu/Kannada/Malayalam substrate), Bengali-substrate
TranscriptionVerbatim, native-speaker, second-pass reviewed
Structured dataset packages ready for delivery — supporting 100 speakers of indian english conversational speech
Structured dataset packages ready for delivery
03

Designing the scenarios for Indian English

  • 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 Indian English specifically: Retroflex realisation of /t/ and /d/
  • Code-mixing handled explicitly rather than edited out — Indian English embeds Hindi and regional discourse markers, kinship terms, and food and place vocabulary that Western English lexicons lack.
04

Running a pilot cohort Indian English 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.

Balance by substrate language, not by city alone, and tag each speaker so accent-band evaluation is possible after delivery.

ParameterAt this volume
CitiesOne — Bengaluru, Delhi
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 Indian English
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 Indian English forms that younger urban speakers have lost
RegionPan-India, with distinct regional accent bands and othersDialect spread across 5 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

Indian English-specific considerations

  • Retroflex realisation of /t/ and /d/
  • Indian English embeds Hindi and regional discourse markers, kinship terms, and food and place vocabulary that Western English lexicons lack.
  • Commercial English ASR is trained overwhelmingly on US and UK speech. Indian English accent data with substrate-language tagging is the fastest way to close the accuracy gap for Indian deployments.
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
  • Indian-specific vocabulary flagged as errors by spellcheck-driven QA
  • Numbers spoken in lakhs and crores mis-normalised into millions

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 Indian English

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
  • Indian English carries 5 recognised varieties across Pan-India, with distinct regional accent bands, so the quota matrix is wider than the headline volume suggests
  • Commercial English ASR is trained overwhelmingly on US and UK speech. Indian English accent data with substrate-language tagging is the fastest way to close the accuracy gap for Indian deployments.
10

Deliverables

  • WAV audio to your naming convention, with the per-file manifest
  • Verbatim 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
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 Indian English 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 Indian English 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 Indian English 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 Indian English dataset

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

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