Application of a Head-Contact Microphone to Hands-Free Speech Communication under Hazardous Conditions
George J. Sebesta, Arthur J. Mellen, Alan Hofer · The Journal of the Acoustical Society of America · 1967
Speech communication is required in certain hazardous conditions where the hands must be left free, such as military operations involving searching tunnels and operation of open vehicles such as a motorcycle. A compact field telephone has been developed for the former application, utilizing a head-contact inertia-operated microphone and logarithmically responsive amplifier. These components and a battery are assembled on a specially-designed cap. A reel carrying a half-mile of disposable cable is worn on the belt. The microphone is of the variable-reluctance balanced-armature type. The components are described.