Stereo zoom microphone for consumer video cameras
Mitsuharu Matsumoto, Hiroyuki Naono, H. Saitoh, Kouta Fujimura, Yoshiaki Yasuno · IEEE Transactions on Consumer Electronics · 1989
A compact, built-in stereo zoom microphone for consumer video cameras is described. This system provides for automatic adjustment of the audio mixing ratio, interlocked to the optical zoom lens to achieve psychoacoustically balanced natural sound. The system is designed to work in a full-stereo recording condition at viewing angle and a monaural super-directional recording condition in the telescopic mode, in conjunction with control of the optical zoom lens. The sensitivity is modified in accordance with zooming magnification of the lens. Results of an experiment performed to evaluate the acoustic zoom effect and the coordination between image and sound show that this system has psychoacoustically better results than the conventional monaural-type zoom microphone.>