Skip to content

Audio format

The Audio Files Format settings control the codec, channel layout, and audio filters the recorder applies when writing recordings. They trade storage size against audio quality — and they matter for analytics: stereo recordings keep the two parties on separate channels, which improves speaker attribution in transcripts.

Where: Administration › Storage › Audio Files Format; click Edit Configuration to change:

  • File format — WAV, MP3, or Auto (default MP3).
  • Audio format — Mono or Stereo (default stereo). Keep stereo where the capture interface delivers the parties separately — channel separation is what lets the transcription engine attribute speech to the right speaker.
  • AGC filter — Automatic Gain Control normalizes volume levels between the two audio channels (default on), with AGC maximum gain level (1.0–5.0, default 3.0) limiting amplification so faint noise is not boosted to full volume.
  • PLC filter — Packet Loss Concealment improves audio quality under slight packet loss (less than 5%; default on).
  • MP3 bitrate — 8/16/24/32/64 kbps (default 16). The value applies per audio channel and per 8,000 Hz of sample rate — a stereo file at 16,000 Hz is stored at four times the configured bitrate.
  • MP3 quality — the encoder's quality/speed trade-off, 0 (best, very slow) to 9 (worst, very fast), default 5.

The settings are stored as base recorder settings shared by all recorders (Audio category); use per-recorder overrides under Recorder servers for exceptions.

Changing format for existing recordings

These settings affect newly captured audio only. To re-encode files that already exist — for example, converting old WAV archives to MP3 to reclaim space — run the Convert audio files job; see File maintenance jobs.