Dataset specification · Evaluation cohort
500 speakers of Assamese Conversational Speech
An evaluation cohort build of 500 speakers of Assamese conversational speech. Speaker-count-driven work: verification, diarisation and accent robustness, where breadth matters more than hours. 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 speakers
- Scale
- Evaluation cohort
- Per speaker
- 20–30 minutes of accepted audio per speaker, in pairs
- Accepted yield
- 55–65% of recorded time is accepted
How Assamese 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 | Assamese (as-IN, Assamese (Eastern Nagari)) |
| Volume | 500 speakers |
| Equivalent | 250 hours at 30 minutes per speaker |
| 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 | Kamrupi, Goalparia, Upper Assam (Sibsagar standard), Barak Valley contact varieties |
| Transcription | Verbatim, native-speaker, second-pass reviewed |

Designing the scenarios for Assamese
- 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 Assamese specifically: Assamese has the voiceless velar fricative /x/, unique among major Indian languages and routinely mis-modelled
- Code-mixing handled explicitly rather than edited out — Assamese speech mixes Hindi, English and Bengali, with substantial contact influence in Barak Valley and tea-garden communities.
Running an evaluation cohort Assamese build
Six to eight weeks. Speaker-count targets front-load recruitment, so the coordinator team is proportionally larger than an equivalent hours-based build.
Four batches, each one a demographically complete slice rather than a convenient chunk, so early batches are usable for training on their own.
Expect longer fielding times and higher per-hour cost than for Hindi or Marathi; the speaker pool with transcription-grade literacy is smaller.
| Parameter | At this volume |
|---|---|
| Cities | Three to four — Guwahati, Jorhat, Dibrugarh, Silchar, Tezpur |
| Studios | Four rooms |
| Recruiters | Four coordinators |
| Audio yield | ~250 hours at 30 minutes per speaker |
| Sessions per day | 25–30 |
| Team | 1 programme lead, 4 coordinators, 8 engineers, 14 transcribers, 2 QA leads |
Cohort design
At 500 speakers 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 Assamese |
|---|---|---|
| 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 Assamese forms that younger urban speakers have lost |
| Region | Assam / Arunachal Pradesh / parts of Nagaland and Meghalaya 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 |
Assamese-specific considerations
- Assamese has the voiceless velar fricative /x/, unique among major Indian languages and routinely mis-modelled
- Assamese speech mixes Hindi, English and Bengali, with substantial contact influence in Barak Valley and tea-garden communities.
- Extremely low-resource. Almost no spontaneous Assamese speech data exists publicly, and non-standard dialects have none.
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
- Bengali characters substituted for Assamese ৰ / ৱ
- Goalparia and Kamrupi forms standardised to Sibsagar Assamese
100% technical QA, 15% content QA, plus mandatory duplicate-speaker detection across cities.
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 cohort in Assamese
Cost at this band is driven by: Cohort breadth and screening depth, not recorded hours.
- Duplicate speakers across cities inflate the apparent cohort and quietly corrupt speaker-disjoint splits
- Recruiting for breadth tempts coordinators toward the easiest available demographic, which needs weekly quota audit
- Assamese carries 4 recognised varieties across Assam, Arunachal Pradesh, parts of Nagaland and Meghalaya, so the quota matrix is wider than the headline volume suggests
- Extremely low-resource. Almost no spontaneous Assamese speech data exists publicly, and non-standard dialects have none.
Deliverables
- WAV audio to your naming convention, with the per-file manifest
- Verbatim Assamese (Eastern Nagari) 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 speakers of Assamese enough?
Enough for reliable per-dialect evaluation and for training speaker-verification and diarisation systems.
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 cohort Assamese build take?
Six to eight weeks. Speaker-count targets front-load recruitment, so the coordinator team is proportionally larger than an equivalent hours-based build. Four batches, each one a demographically complete slice rather than a convenient chunk, so early batches are usable for training on their own.
What does 500 speakers of Assamese conversational speech cost?
Quoted per delivered hour against this specification. At this band the drivers are cohort breadth and screening depth, not recorded hours. Send the spec and you get one fixed figure.
How much QA is applied at this volume?
100% technical QA, 15% content QA, plus mandatory duplicate-speaker detection across cities.
Quote this Assamese dataset
500 speakers, conversational speech, Assamese — evaluation cohort. Adjust anything and send it.