Mono is audio with a single channel — one waveform reproduced identically on every speaker. It is the natural choice for anything centered on a single source: dialogue, voice-over, podcasts, and the vast majority of real-time voice calls, where one microphone captures one speaker. Mono is also bandwidth-cheap, which matters in WebRTC and telephony. Its quiet virtue is robustness: a mono mix has no phase relationship to collapse, so it survives summing, downmixing, and poor playback unchanged. Checking that a stereo or surround mix still sounds right when folded to mono — 'mono compatibility' — is a standard broadcast quality gate.
The book · Volume 4 of 7
Audio for Video: A Complete Guide to Sound in Video Products: From PCM and Codecs to Loudness, Accessibility, and Real-Time Voice Processing
Mono is the right default for voice calls and dialogue, but a careless stereo-to-mono fold can cancel parts of a mix. This volume covers mono in detail with channel layouts, downmix rules, speech codecs and loudness, so you can decide where a single channel saves bandwidth and where stereo is worth keeping. Written by Nikolay Sapunov, CEO at Fora Soft.
Deciding whether to send mono or stereo audio in your calls and streams?
Tell us your content and bandwidth limits and we will recommend mono or stereo per use case, with codec settings and downmix rules. 250+ video products shipped since 2005.
