A system for reducing audio noise, comprising: an Input component configured so as to receive an input time-domain signal X(n) and generate an Input frequency-domain signal X(k) and a power spectrum PowX(k) of said input frequency-domain signal, wherein said power spectrum r PowX(k) j comprises N frequency bins corresponding to N sampled values of said input time-domain signal: a noise-activity detector for detecting presence of noise activity in said power spectrum; a white-noise detector configured to detect presence of white noise in said power spectrum; a network tone detector j configured to detect presence of a network tone in said power spectrum; an adjustment component configured so as to: generate an adjustment power spectrum PowA(k), comprising an estimated noise power spectrum and a spectral gain mSpectralGain(k,m), based on detection of said presence of said noise activity, said white noise, and said network tone, such that: the generation of said adjustment power spectrum PowA(k) comprises scaling said spectral gain by a selected amount if a j network tone is not detected by said network-tone detector and noise activity is detected by said noise-activity detector, and wherein the generation of said adjustment power spectrum PowA(k) further comprises adjusting the spectral gain for white noise if network tone Is not detected by said network-tone detector and said white noise Is detected by said white-noise detector; combine said adjustment power spectrum PowA(k) with said input frequency-domain signal X(k) so as to generate an output frequency-domain signal Y(k); and an output component configured so as to generate an output time-domain signal Y(n) based on said output frequency-domain signal. an Input component configured so as to receive an input time-domain signal X(n) and generate an Input frequency-domain signal X(k) and a power spectrum PowX(k) of said input frequency-domain signal, a noise-activity detector for detecting presence of noise activity in said power spectrum; a white-noise detector configured to detect presence of white noise in said power spectrum; a network tone detector j configured to detect presence of a network tone in said power spectrum; an adjustment component configured so as to: generate an adjustment power spectrum PowA(k), comprising an estimated noise power spectrum and a spectral gain mSpectralGain(k,m), based on detection of said presence of said noise activity, said white noise, and said network tone, such that: the generation of said adjustment power spectrum PowA(k) comprises scaling said spectral gain by a selected amount if a j network tone is not detected by said network-tone detector and noise activity is detected by said noise-activity detector, and wherein the generation of said adjustment power spectrum PowA(k) further comprises adjusting the spectral gain for white noise if network tone Is not detected by said network-tone detector and said white noise Is detected by said white-noise detector; combine said adjustment power spectrum PowA(k) with said input frequency-domain signal X(k) so as to generate an output frequency-domain signal Y(k); and generate an adjustment power spectrum PowA(k), comprising an estimated noise power spectrum and a spectral gain mSpectralGain(k,m), based on detection of said presence of said noise activity, said white noise, and said network tone, such that: the generation of said adjustment power spectrum PowA(k) comprises scaling said spectral gain by a selected amount if a j network tone is not detected by said network-tone detector and noise activity is detected by said noise-activity detector, and wherein the generation of said adjustment power spectrum PowA(k) further comprises adjusting the spectral gain for white noise if network tone Is not detected by said network-tone detector and said white noise Is detected by said white-noise detector; combine said adjustment power spectrum PowA(k) with said input frequency-domain signal X(k) so as to generate an output frequency-domain signal Y(k); and the generation of said adjustment power spectrum PowA(k) comprises scaling said spectral gain by a selected amount if a j network tone is not detected by said network-tone detector and noise activity is detected by said noise-activity detector, and wherein the generation of said adjustment power spectrum PowA(k) further comprises adjusting the spectral gain for white noise if network tone Is not detected by said network-tone detector and said white noise Is detected by said white-noise detector; combine said adjustment power spectrum PowA(k) with said input frequency-domain signal X(k) so as to generate an output frequency-domain signal Y(k); and an output component configured so as to generate an output time-domain signal Y(n) based on said output frequency-domain signal.