Method for signal nonlinear distortion detection and adaptive gain control

Abstract

An apparatus includes a microphone to generate a voice signal. The apparatus further includes an adjustable gain circuit coupled to the microphone to selectively apply a gain to the voice signal. In addition the apparatus includes an analog front end circuit coupled to the adjustable gain circuit to transmit the voice signal via a telephone line. Also, the apparatus includes a control circuit coupled to the adjustable gain circuit. The control circuit is operative to detect an average level of energy of the voice signal outside of a voice frequency band. The control circuit is further operative to control, based at least in part on the detected average level of energy, an amount of gain applied to the voice signal by the adjustable gain circuit.

Dependencies are inferred from the claim text.