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Recording specs

How do you collect noisy and far-field speech data?

Updated 2026-08-01 · 4 min read

Field recording session with a rural speaker in India — illustration for: How do you collect noisy and far-field speech data?

Short answer

Collect real noise rather than adding it later wherever the deployment allows. Real environments contribute noise, reverberation, speaker movement and Lombard effect — people speak differently in noise — and only the first of those can be simulated convincingly by mixing noise into clean audio. For far-field work, record at the microphone geometry and distances of the device, in rooms with the reverberation characteristics of the target environment, with parallel close-mic capture as a clean reference.

Key takeaways

The argument at a glance1Lombard effect means noisy-environment speech is different speech, not clean speech plus noise.2Record at the device's real microphone geometry for far-field models.3Parallel close-mic reference tracks make noisy corpora far more useful.
  • Lombard effect means noisy-environment speech is different speech, not clean speech plus noise.
  • Record at the device's real microphone geometry for far-field models.
  • Parallel close-mic reference tracks make noisy corpora far more useful.

Why augmentation is not enough

Mixing noise into clean recordings changes the signal but not the speaking behaviour. In real noise people raise volume, slow down, hyper-articulate and shift pitch. Models trained only on augmented data see none of that.

Far-field specifics

Distance, room reverberation and microphone array geometry dominate far-field performance. Record with the actual array where possible, at the distances users will stand, in rooms representative of the deployment — Indian homes, shop floors, car interiors.

Annotators writing prompts and responses for LLM training data — recording specs context for How do you collect noisy and far-field speech data
Annotators writing prompts and responses for LLM training data

Parallel references

A close-mic track recorded simultaneously gives an aligned clean reference for every noisy utterance. That pairing supports enhancement training, robustness evaluation and honest transcription of audio that would otherwise be ambiguous.

Specifying noise

Describe the environments, approximate SNR bands and the proportion of the corpus in each. 'Some noisy data' is not specifiable and will be delivered as whatever was convenient.

Frequently asked questions

How do you collect noisy and far-field speech data?

Collect real noise rather than adding it later wherever the deployment allows. Real environments contribute noise, reverberation, speaker movement and Lombard effect — people speak differently in noise — and only the first of those can be simulated convincingly by mixing noise into clean audio. For far-field work, record at the microphone geometry and distances of the device, in rooms with the reverberation characteristics of the target environment, with parallel close-mic capture as a clean reference.

Why augmentation is not enough?

Mixing noise into clean recordings changes the signal but not the speaking behaviour. In real noise people raise volume, slow down, hyper-articulate and shift pitch. Models trained only on augmented data see none of that.

Far-field specifics?

Distance, room reverberation and microphone array geometry dominate far-field performance. Record with the actual array where possible, at the distances users will stand, in rooms representative of the deployment — Indian homes, shop floors, car interiors.

Parallel references?

A close-mic track recorded simultaneously gives an aligned clean reference for every noisy utterance. That pairing supports enhancement training, robustness evaluation and honest transcription of audio that would otherwise be ambiguous.

Related reading

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