What is a Flanger?

A flanger is an audio effect that creates a sweeping, swirling sound by mixing an audio signal with a slightly delayed version of itself. The delay time is very short and continuously changes, causing the two signals to interact and produce a series of moving peaks and dips in the frequency spectrum. This effect creates the distinctive “whooshing” or jet-like sound often associated with flanging.

The flanger works by using a short delay that is modulated by a low-frequency oscillator (LFO). As the delay time changes, the phase relationship between the original signal and the delayed signal shifts. This creates a pattern called comb filtering, where certain frequencies are reinforced while others are reduced, producing the sweeping sound.

Flanger effects are commonly used on guitars, vocals, drums, and synthesizers to add movement and texture to a track. The effect became popular in rock and psychedelic music and later appeared in many electronic and experimental recordings. By adjusting controls such as delay time, feedback, and modulation rate, producers can create subtle or dramatic flanging effects.