Band buzz (4)
I believe the answer is:
ring
I believe this is a double definition.
'band' is the first definition.
(a ring is a band of metal)
'buzz' is the second definition.
(buzz can mean a ringing noise)
(Other definitions for ring that I've seen before include "It's carried by Frodo" , "'It's a square, strangely, for boxers (4)'" , "Sound a doorbell" , "place for fight" , "Contact" .)