THE "EARS" OF RADIO

Radio Record, Volume I, Issue 35, 16 March 1928, Page 11

THE "EARS" OF RADIO

PLACING THE MICROPHONES LATEST STUDIO PRACTICE, WHEN man seeks to improve on any mechanical arrangement he looks to Nature. That is why the radio experts, wishing to improve on the "hearing" capabilities of microphones, have stud.ed the position of the human ears. Two ears are better than 0.1, no matter how acute that one may be. Two ears give a sense of direction in regard to the origin of the sound that is heard. Since birth, we have trained ourselves unconsciously to locate the direction of sounds by means of ous binaural sense, To determine the direction, we, instinctively face it. This unconscious action, common to all animals and birds, seems merely to bring both ears equidistant from the source under which conditions the binaural sense is most accurate and the audition image is binaurally centred im the head. If a sound is to the right of us, the right ear, being more exposed to the sound, receives a stronger impression than the left ear, which is somewhat in the shadow of the head, so to speak, and the sound waves take slightly longer to reach it. The two ears unconsc.ously take cogutsance of this binaural time difference and give us a resul‘ant audible impression which we have trained ourselves from childhood to regard as a sense of direction. It is this interpretation of a time interval in terms of direction which is known as the binaural sense. It is this principile that radio engineers are now applying to the placing of the microphones. In listening to a band, orchestra, or choir, for instance, the two human ears, because of their position can hear and detect the position of the various instruments or singers, whereas one ear could not, Similarly, two or more microphones are more efficient than one on such occasions. For some time now at 3YA_ two microphones placed in an angular position similar to that of the human ears have been used even for soloists, and the result has been a decided improvement on that obtained by one microphone.