lav·a·liere 
(lăv′ə-lîr)
(lăv′ə-lîr)n.
1. also la·val·lière (lä′vä-lyâr) A pendant worn on a chain around the neck.
2. A small microphone that is worn around the neck.
[French lavallière, type of necktie with a large knot, after Françoise Louise de la Baume Le Blanc, Duchesse de La Vallière (1644-1710), lover of Louis XIV.]