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Dataset specification · Pilot cohort

100 speakers of Malayalam Scripted Speech

A pilot cohort build of 100 speakers of Malayalam scripted speech. Establishing whether a cohort definition is recruitable at all before it is scaled. Speakers read prompts from a phonetically balanced script shown one line at a time, with retakes on any flubbed or misread line.

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Structured dataset packages ready for delivery — 100 speakers of Malayalam Scripted Speech
Volume
100 speakers
Scale
Pilot cohort
Per speaker
20–30 minutes of accepted audio per speaker
Accepted yield
85–90% of recorded time is accepted
01

How Malayalam scripted speech is captured

Speakers read prompts from a phonetically balanced script shown one line at a time, with retakes on any flubbed or misread line.

A 45-minute booth session yields roughly 300–400 prompts. One file per utterance, cut at the prompt boundary, so alignment is exact before any forced-alignment pass runs.

Yield at this style: 85–90% of recorded time is accepted. Prompt-level retakes catch problems inside the session, so very little is discarded afterwards. This is the highest-yield style we run.

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
LanguageMalayalam (ml-IN, Malayalam)
Volume100 speakers
Equivalent50 hours at 30 minutes per speaker
Speech typeScripted Speech
Per speaker20–30 minutes of accepted audio per speaker
File granularityOne WAV per prompt, named by prompt ID and speaker ID
Prompt coverageTriphone-balanced script with digit, date, name and domain-lexicon blocks
Leading/trailing silence200 ms padded, verified automatically on every file
AlignmentPrompt text is ground truth; deviations are flagged rather than silently corrected
DialectsThiruvananthapuram, Kochi (central), Malabar / Kozhikode, Thrissur
TranscriptionVerbatim, native-speaker, second-pass reviewed
Transcriber timestamping Indian language audio — supporting 100 speakers of malayalam scripted speech
Transcriber timestamping Indian language audio
03

Designing the script for Malayalam

  • Script built for triphone coverage rather than word coverage, so rare phone contexts appear often enough to train on
  • Digit strings, dates, currency and person names blocked separately, because these are where deployed ASR actually fails
  • Domain lexicon injected from your product vocabulary when you supply one
  • Sentence-length distribution spread deliberately, since all-short prompts produce a model that cannot handle long utterances
  • Built against Malayalam specifically: One of the most consonant-dense Indian languages; long geminates and clusters raise word error rates sharply
  • Code-mixing handled explicitly rather than edited out — Manglish is standard in urban and professional speech, with heavy English noun and verb insertion.
04

Running a pilot cohort Malayalam 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.

Budget higher transcription effort per audio hour for Malayalam than for Hindi; speech rate and morphology make it slower to annotate.

ParameterAt this volume
CitiesOne — Kochi, Thiruvananthapuram
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.

Requires literate speakers comfortable reading aloud in the target script, which is the main constraint on cohort breadth and has to be actively counterweighted.

DimensionTypical splitWhy it matters for Malayalam
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 Malayalam forms that younger urban speakers have lost
RegionKerala / Lakshadweep / Puducherry (Mahe) 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

Malayalam-specific considerations

  • One of the most consonant-dense Indian languages; long geminates and clusters raise word error rates sharply
  • Manglish is standard in urban and professional speech, with heavy English noun and verb insertion.
  • Central Kerala news-reading dominates public data. Malabar and southern varieties, and fast conversational speech generally, are missing.
07

Quality gates for scripted speech

  • Prompt-to-audio match verified by a native reviewer; a misread line is a rejected file, not an edited transcript
  • Hyperarticulation flagged — a speaker over-enunciating because they are reading produces audio that does not match deployment
  • Clipping and truncation checked at both utterance boundaries
  • Per-speaker prompt coverage confirmed, so no speaker silently skips a block
  • Old vs new script (chillu characters, Unicode normalisation) mixed within a dataset
  • Fast speech leads to dropped-word transcription errors without a second-pass QA

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

08

What goes wrong on scripted speech sessions

  • Reading voice: flat prosody and unnatural stress that trains a model on speech nobody actually produces
  • Prompt fatigue in the back half of long sessions, where accuracy drops and pace flattens
  • Speakers who are not fluent readers, which quietly biases the cohort toward higher education bands
  • Script leakage across speakers, producing a corpus that memorises sentences instead of covering sounds
09

Risks at pilot cohort in Malayalam

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
  • Malayalam carries 5 recognised varieties across Kerala, Lakshadweep, Puducherry (Mahe), so the quota matrix is wider than the headline volume suggests
  • Central Kerala news-reading dominates public data. Malabar and southern varieties, and fast conversational speech generally, are missing.
10

Deliverables

  • WAV audio to your naming convention, with the per-file manifest
  • Verbatim Malayalam transcripts with utterance-level timestamps
  • Prompt ID mapped to every utterance
  • Verbatim deviation flags where the speaker departed from the script
  • Per-utterance SNR and duration in the manifest
  • 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

  • ASR acoustic model baselines
  • TTS voice building where a single speaker is recorded at depth
  • Pronunciation lexicon and G2P validation
  • Forced-alignment and phone-boundary work

Scripted audio contains no disfluencies, no false starts and no natural turn-taking. A model trained on it alone degrades sharply on real spontaneous input, so it is a baseline layer rather than a complete training set.

Frequently asked

Is 100 speakers of Malayalam 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 scripted speech rather than another speech type?

ASR acoustic model baselines, TTS voice building where a single speaker is recorded at depth, Pronunciation lexicon and G2P validation are what this style is the right input for. Scripted audio contains no disfluencies, no false starts and no natural turn-taking. A model trained on it alone degrades sharply on real spontaneous input, so it is a baseline layer rather than a complete training set.

How long does a pilot cohort Malayalam 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 Malayalam scripted 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 Malayalam dataset

100 speakers, scripted speech, Malayalam — pilot cohort. Adjust anything and send it.

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