lavalier microphone

Noun

 * 1)   A small microphone worn like a lavalier (suspended from a cord worn around the neck).
 * 2)   Any small, hands-free microphone which is worn attached to the body or clothes.

Usage notes
The style of microphone described in is obsolete, having been superseded by lapel microphones in the late 20th century. The meaning of the term expanded to describe any body-worn microphone.