Wah

Wah Pedal Functions & Basics

Wah (or Wah-Wah) Pedals were originally intended to mimic the sound of a human voice. They are often referred to as "bandpass" filters.....basically sound filters that allow frequencies within a certain range and reject frequencies outside of that range. These select frequencies are what you hear when you rock the pedal back and forth, creating that unmistakeable "wah" sound.

Although not necessarily true pitch modulation pedals, wah (or wah-wah) pedals tend to fall into that family.