| 摘要 |
<p>The sound amplification system which can be introduced between a microphone and a loudspeaker system can be used to amplify a number of voices of different pitch to give the sound of a choir, or to amplify instruments to give the impression of an orchestra. The sounds, including overtones and undertones are multiplied over their different pitches so that the natural characteristics are maintained. The number of the multiplying sounds and their pitch is determined according to a program using e.g. a perforated tape. A control system may be employed where the various factors for multiplication may be selected by a set of push-buttons.</p> |
