Examples of membranophones include all types of drums including the petia, sogo, bongo, the bedhug and the kazoo. In a membranophone, sound is produced by a vibrating skin stretched over an opening.
Drums are divided into three different categories. Friction drums are those drums that need a rubbing motion to produce sound. Struck drums are those drums that produce sound when hit with a hand, stick or other object. String drums have a knotted string attached to the skin. When the string is pulled, sound is produced.
A kazoo works by modifying sound produced by something else and is considered to be a singing membranophone.