Acoustic coupling structure for microphone

Abstract

The microphone of an electronic device is mounted within the housing of the device, and may be a microphone cartridge having a sound opening exposed to a sound chamber within the housing. The device may be a portable radio transmitter and receiver wherein the housing has a wall with a grille screen for providing sound transmission between the inside and the outside of the housing. A cavity is provided inside the housing adjacent the screen for receiving sound to be applied to the microphone. A sound passage connects the cavity to the sound chamber which acts as a reinforcing chamber to apply sound to the microphone. In a radio transmitter and receiver, a loudspeaker may be positioned to project sound through the grille screen, and the cavity between the loudspeaker cone or diaphragm and the screen forms the cavity for collecting the sound. The passage for applying sound to the sound reinforcing chamber may be provided by an opening in the screen and an opening in a felt disc covering the screen which cooperate with a recess in the housing. The acoustic coupling structure can be provided by a sound collecting cavity and passage which are independent of a loudspeaker.