Simple Explanation

A sound distortion that happens when a signal is mixed with a slightly delayed version of itself, causing a pattern of peaks and dips in the sound.

Concise Technical Definition

An interference pattern resulting from the summation of a signal with its delayed version, creating periodic notches and peaks in the frequency response that resemble the teeth of a comb.

Layman-Friendly Analogy

Like two people singing the same song just slightly out of sync—some parts get louder, others cancel out. The result sounds weird and uneven, like an echo warping the tune.

Industry Usage Summary

Common in live sound and studio monitoring, particularly in untreated rooms where reflections from surfaces combine with direct sound. Engineers aim to avoid comb filtering through proper mic placement, speaker positioning, and acoustic treatment. Also used creatively in music production as an effect.

Engineering Shortcut

Signal + Delayed Copy = Comb Filtering (delay < 10ms → audible notches in response).

Full Technical Explanation

A comb filter occurs when a signal is combined with a delayed version of itself, typically due to acoustic reflections or digital processing. The delay causes constructive and destructive interference at regular frequency intervals, leading to a pattern of notches (cancellations) and peaks (reinforcements). The name comes from the comb-like shape of the frequency response curve. Delay time determines spacing between notches. Common in audio systems, acoustics, DSP, and microphone placement scenarios.