Electrical audio signal processing systems and devices – Including amplitude or volume control
Patent
1994-07-14
1997-12-23
Lee, Thomas D.
Electrical audio signal processing systems and devices
Including amplitude or volume control
381 94, H04R 100, H03G 900, H03G 300
Patent
active
057013527
ABSTRACT:
An improved automatic gain control circuit for a telephonic headset having a gain control stage in the audio signal path to attenuate tones, in which the gain is controlled by a control signal. A peak filter and an average filter generate signals proportional to the peak and average levels of the input signal, respectively. The signals are compared and a control signal is generated based on the relative signal levels. When the average signal exceeds a predetermined fraction of the peak signal, the circuit recognizes the signal as a tone and generates a control signal that causes the gain control stage to increase attenuation of the input signal.
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Lewkowicz et al. Automatic Gain Control With Equalizer; IBM Corp 1979 pp. 3569-3576.
Lewkowicz, J. and O'Day, R.L; Automatic Gain Control and Equalizer; IBM Technical Disclosure Bulletin; Feb. 1979, vol. 21, No. 9, pp. 3569-3570.
BellSouth Corporation
Grant II Jerome
Lee Thomas D.
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