A stomp box or stompbox is a simple percussion instrument consisting of a small wooden box placed under the foot, which is tapped or stamped on rhythmically to produce a sound similar to that of a bass drum. A stomp box allows a performer such as a singer or guitar player to create a simple rhythmic self-accompaniment. Stompboxes are most commonly used in American folk and blues music, but are found across the musical spectrum: Bat for Lashes, for instance, has a very large (1m2) stompbox which she strikes with a staff to accompany herself.
In modern use, a microphone, or more commonly a simple piezo transducer, is usually placed inside the box to allow amplification. Others (such as the PorchBoard Bass) use sensors designed to produce low-end frequencies. There are commercially produced stomp boxes available (see photos), but performers often simply put a microphone inside whatever box they have handy. Homemade stomp boxes can also be more sophisticated, and can include features such as a built-in preamp.