Clipping is the hard distortion that occurs when a signal tries to exceed the maximum level the system can represent — 0 dBFS in the digital domain — and its peaks are simply flattened to the ceiling. The squared-off waveform is rich in harsh high harmonics, the crackle you hear on an overdriven recording. Digital clipping is unforgiving and, once printed into a file, permanent: the lost peak information cannot be recovered. It happens at capture if input gain is too high, and in processing if gains sum past full scale. Defences are adequate headroom, a true-peak limiter before the ceiling, and metering that catches consecutive max-value samples.
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
Clipping destroys the peaks of a recording for good, and in calls it often comes from gain control fighting a hot microphone. Volume 4 covers clipping in detail: bit depth and headroom, dynamic range, loudness and true peak, limiters, and automatic gain control in real-time voice processing. Written by Nikolay Sapunov, CEO at Fora Soft.
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