Masahiro Takahashi, Yoshikatsu Watanabe: Vehicle sound system. Alpine Electronics, Guy W Shoup, Norman R Klivans, April 20, 1993: US05204971 (39 worldwide citation)

A sound system for a vehicle detects the amount of noise, such as road noise, and automatically controls the audio volume in accordance with the noise amount. There are provided a plurality of tables, in which the relationships among the present volume, the noise amount and the volume increase amoun ...

Yoshikatsu Watanabe, Takashi Miyake, Masatoshi Ito, Yoshio Imanishi: Automatic sound volume control method. Alpine Electronics, Guy W Shoup, Norman R Klivans, Patrick T Bever, July 18, 1995: US05434926 (24 worldwide citation)

An automatic volume control to prevent the listener from having an odd sensation is obtained with a plurality of conditions taken into considerations. A plurality of control rules required to infer using fuzzy logic a volume correcting value on the basis of frequency band component levels, L, M and ...

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