Abstract

Disclosed are apparatus and method for modulating color contributions in visual displays with audio modulating signals. Particular embodiments disclosed separate input audio frequency signals into modulating signals characterized by particular frequency ranges. At least one such modulating signal is operated on by a gating circuit controlled by enabling signals from a voltage controlled oscillator. A level detector samples the modulating signal and feeds control signals to the voltage controlled oscillator in response to values of amplitude detected in the modulating signal. Generation and processing of the modulating signals may be provided as part of a visual display system such as a color television receiver or eidophor system, or such signals may be transmitted through the antenna input of such a system. Each electron gun in the visual display system is then modulated by a different modulating signal, resulting in varied color displays in response to the frequency and magnitude of the input audio frequency signals.