General aspects of hands-free telephony

The use of a simple hands-free telephone set with distant talking and loudspeaker reception introduces transmission degradation not encountered with hand-set usage. Proper usage and good acoustic surroundings reduce these impairments to a point where satisfactory transmission is obtained on a large percentage of calls in today´s plant which is designed to have transmission margin on a good proportion of all calls. There are several potentialities for improving the hands-free telephone set but it is not yet clear whether or not the gain will justify the added complexity or the added restrictions placed on the user. It is to be expected that very excellent performance could be obtained from a unit such as a booth which combines optimum instrument design with favorable environment.