Patent ID: 7908138

Claim:
A method of reducing noise in an input signal Yin that may contain speech comprising: obtaining a noise level estimate signal (Noise Level) of the noise in the input signal Yin; and when (|Yin|>c 1 α Noise Level), outputting a signal Yin; when c 2 α(Noise Level)<|Yin|<c 3 α(Noise Level), outputting a signal sign(Yin){|Yin|-c 4 α(Noise Level)}; when {α(Noise Level)+β|Yin|}<|Yin|<c 5 α(Noise Level), outputting a signal sign(Yin){|Yin|-α(Noise Level)}; and when |Yin|<{α(Noise Level)+β|Yin|}, outputting a signal βYin, wherein |Yin| is the magnitude of the input signal Yin, and c 1 , c 2 , c 3 , c 4 , and c 5 are numeric constants, and wherein α and β are scaling factors determined by comparing the instantaneous peak level of the input signal with the noise level estimate.