#acoustic_device  a device for amplifying or transmitting sound
  supertype:  device  an instrumentality invented for a particular purpose; "the device is small enough to wear on your wrist"; "a device intended to conserve water"
  subtype:  bell  a hollow device made of metal that makes a ringing sound when struck
     subtype:  church_bell  a bell in a church tower (usually sounded to summon people to church); "church bells were ringing all over town"
     subtype:  cowbell  a bell hung around the neck of cow so that the cow can be easily located
     subtype:  death_bell__deathbell__death_knell__deathknell  a bell rung to announce a death
     subtype:  dinner_bell  a bell rung to announce that dinner has been served
     subtype:  electric_bell  a bell activated by the magnetic effect of an electric current
        subtype:  telephone_bell__telephonebell  electric bell that rings to signal a call
     subtype:  fire_bell  a bell rung to give a fire alarm
     subtype:  Liberty_Bell  the bell of Independence Hall; rung 8 July 1776 to announce the signing of the Declaration of Independence
     subtype:  school_bell  a bell rung to announce beginning or ending of class
     subtype:  sheep_bell__sheepbell  a bell hung round the neck of a sheep so that the sheep can be easily located
     subtype:  shop_bell  a bell attached to the door of a small shop; warns the proprietor that a customer has entered the shop
     subtype:  sleigh_bell__cascabel  bell attached to a sleigh, or to harness of horse pulling a sleigh
     subtype:  warning_bell__warningbell  a bell used to sound an alarm
  subtype:  birdcall  a device for imitating a birdcall
  subtype:  ear_trumpet__eartrumpet__hearing_aid__hearingaid  a conical acoustic device formerly used to direct sound to the ear of a hearing-impaired person
  subtype:  megaphone  a cone-shaped acoustic device held to the mouth to intensify and direct the human voice
  subtype:  mouthpiece  an acoustic device; the part of a telephone into which a person speaks
  subtype:  mute  a device used to soften the tone of a musical instrument
     subtype:  sordino__sourdine  a mute for a violin
  subtype:  silencer.acoustic_device__muffler  a tubular acoustic device inserted in the exhaust system that is designed to reduce noise
  subtype:  siren.acoustic_device  an acoustic device producing a loud often wailing sound as a signal or warning
  subtype:  slapstick.acoustic_device  acoustic device consisting of two paddles hinged together; used by an actor to make a loud noise without inflicting injury when striking someone
  subtype:  speaking_trumpet  a trumpet-shaped acoustic device to intensify and direct the human voice; formerly held to the ear by a hard-of-hearing person
  subtype:  whistle  acoustic device that forces air or steam against an edge or into a cavity and so produces a loud shrill sound
     subtype:  boat_whistle  a whistle on a boat that is sounded as a warning
     subtype:  factory_whistle__factorywhistle  a whistle at a factory that is sounded to announce times for starting or stopping work
     subtype:  steam_whistle__steamwhistle  a whistle in which the sound is produced by steam; usually attached to a steam boiler

No statement uses or specializes acoustic_device; click here to add one.