Noise adaptive automatic gain control circuit

Abstract

A noise adaptive automatic gain control circuit (100) includes an automatic gain control amplifier (105) for automatically adjusting the gain of the circuit (100) in response to an input signal applied to the input. A detector (135) is provided for detecting the presence of any background noise that may be present. Further, a voltage generator (126), a comparator (124), and a microcomputer (150) is provided for dynamically adjusting the gain of the AGC amplifier (105) to substantially prevent the amplification of the background noise. In other aspects of the present invention, a voice lull detector (140) detects voice lulls (402) in the input signal applied to the input. Further, a programmable amplifier (120) substantially maintains the gain of the AGC amplifier (105) to a constant level during voice lulls (402) to prevent excessive amplification.

Dependencies are inferred from the claim text.