Clapper

Noun

 * 1) An object so suspended inside a bell that it may hit the bell and cause it to ring.
 * 2) A wooden mechanical device used as a scarecrow; bird-scaring rattle, a wind-rattle or a wind-clapper.

Thesaurus
Klaxon, bell, boiler factory, boiler room, bull-roarer, catcall, cherry bomb, chimes, church bell, clack, clacker, cowbell, cracker, cricket, dinner bell, dinner gong, doorbell, fire bell, firecracker, gong, gong bell, hand bell, horn, jingle bell, noisemaker, passing bell, rattle, rattlebox, sacring bell, sheepbell, siren, sleigh bell, snapper, steam whistle, telephone bell, ticktack, tintinnabulum, tongue, triangle, whistle, whizgig, whizzer