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Service explainers

What is asr training data and how does it work?

Updated 2026-08-01 · 4 min read

Audio waveforms being prepared as ASR training data — illustration for: What is asr training data and how does it work?

Short answer

Transcribed speech corpora built to train and evaluate automatic speech recognition, with verbatim transcription, timestamps and per-token language tagging where code-mixing occurs. In practice the work runs as style guide authored per language, covering numerals, loanwords, script and disfluency rules, then transcriber calibration round with inter-annotator agreement measurement, then first-pass transcription, and you receive audio plus aligned transcripts (json/tsv, or your schema), style guide as delivered documentation. Transcription adds roughly 1-2 weeks per 100 hours after recording, per language.

Key takeaways

The argument at a glance1Agreement is measured, not assumed. We report word-level agreement on a held-out sample so you can judge label quality bef…2Typical buyers: ASR training, ASR fine-tuning, Domain adaptation.3Recruitment approach: Transcribers are native speakers of the target variety, not of a related standard language.
  • Agreement is measured, not assumed. We report word-level agreement on a held-out sample so you can judge label quality before training on it.
  • Typical buyers: ASR training, ASR fine-tuning, Domain adaptation.
  • Recruitment approach: Transcribers are native speakers of the target variety, not of a related standard language.

What the service covers

Transcribed speech corpora built to train and evaluate automatic speech recognition, with verbatim transcription, timestamps and per-token language tagging where code-mixing occurs.

  • Audio plus aligned transcripts (JSON/TSV, or your schema)
  • Style guide as delivered documentation
  • Inter-annotator agreement report
  • Speaker-disjoint train/dev/test splits

Technical specification

These are defaults, not limits. Where your pipeline requires different values, they replace ours in the statement of work rather than being converted after delivery.

ParameterStandard
Audio16 kHz or 48 kHz PCM WAV
TranscriptionVerbatim, including disfluencies, false starts and fillers
TimestampsUtterance level by default; word level on request
TaggingNoise, overlap, unintelligible, foreign-language and code-switch tags
NormalisationRaw and normalised text columns delivered separately
SplitTrain/dev/test splits with no speaker leakage across splits
Annotator labelling audio segments and speaker turns — service explainers context for What is asr training data and how does it work
Annotator labelling audio segments and speaker turns

How the work runs

  • Style guide authored per language, covering numerals, loanwords, script and disfluency rules
  • Transcriber calibration round with inter-annotator agreement measurement
  • First-pass transcription
  • Second-pass native review
  • Automated consistency checks against the style guide
  • Split generation with speaker-disjoint partitions

Quality control and acceptance

Agreement is measured, not assumed. We report word-level agreement on a held-out sample so you can judge label quality before training on it.

Failures are remedied by re-collection rather than by editing delivered files, because repaired audio carries artefacts that survive into the trained model.

Who this is for

Recruitment for this service works as follows. Transcribers are native speakers of the target variety, not of a related standard language.

  • ASR training
  • ASR fine-tuning
  • Domain adaptation
  • WER benchmarking

Timelines

Transcription adds roughly 1-2 weeks per 100 hours after recording, per language.

Multi-language programmes run in parallel rather than in sequence, so a five-language scope does not take five times as long.

Frequently asked questions

What is included in asr training data?

Audio plus aligned transcripts (JSON/TSV, or your schema), Style guide as delivered documentation, Inter-annotator agreement report, delivered against a written specification with acceptance criteria attached.

How long does asr training data take?

Transcription adds roughly 1-2 weeks per 100 hours after recording, per language.

How is quality measured?

Agreement is measured, not assumed. We report word-level agreement on a held-out sample so you can judge label quality before training on it.

Which languages are supported?

Fifteen Indian languages plus Indian English, including Hindi, Marathi, Tamil, Telugu, Kannada.

Related reading

Turn this into a dataset specification

Tell us the languages, speaker count and minutes. You get a written scope, a protocol and a fixed price within one working day.

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