The talk box is a unique effects unit that allows a musician to shape the sound of an instrument with their mouth. It consists of a pedal containing a speaker driver connected to a plastic tube. The sound from the instrument is sent through the tube and into the musician's mouth. The player then shapes the sound by moving their mouth and tongue as if they were speaking, while a separate microphone captures the result. This creates a 'vocalized' instrument sound, famously heard in Peter Frampton's 'Do You Feel Like We Do' and Joe Walsh's 'Rocky Mountain Way.' It is a physical, mechanical effect that uses the human vocal tract as a natural filter.