Signaling Device

• bell

  A hollow device made of metal that makes a ringing sound when struck.

• whistle

  Acoustic device that forces air or steam against an edge or into a cavity and so produces...

Also contains

• mute

  A device used to soften the tone of a musical instrument.

• mouthpiece

  An acoustic device; the part of a telephone into which a person speaks.

• muffler

  A tubular acoustic device inserted in the exhaust system that is designed to reduce noi...

• siren

  An acoustic device producing a loud often wailing sound as a signal or warning.

• slapstick

  Acoustic device consisting of two paddles hinged together; used by an actor to make a...

• megaphone

  A cone-shaped acoustic device held to the mouth to intensify and direct the human voi...

• hearing aid

  A conical acoustic device formerly used to direct sound to the ear of a hearing-impaired...

• speaking trumpet

  A trumpet-shaped acoustic device to intensify and direct the human voice; formerly...

• birdcall

  A device for imitating a birdcall.