Filter banked gain control of audio in a noisy environment

An apparatus for converting an input signal to an output signal that is distinguishable from a noise, comprising:

• a noise estimator;
• a plurality of signal bandpass filters configured to decompose the input signal into a plurality of signal subbands;
• a plurality of noise bandpass filters configured to decompose estimated noise from the noise estimator into a plurality of noise subbands corresponding to said signal subbands;
• a mechanism for obtaining a power measure of signal subbands from the signal bandpass filters,
• a comparator adapted to compare the power measure of said each signal subband to said power measure of at least one other said signal subband;
• a nullifier adapted to nullify signal subbands when their power measure is exceeded by the power measure of one other signal subband to which they were compared at least by a signal masking threshold;
• and
• circuitry adapted to adjust at least one signal subband to mask a corresponding noise subband.

In a communications system wherein a user alternately receives a received signal in a noisy environment and transmits a transmitted signal, a method for boosting the received signal to overcome the noise, comprising:

• (a) estimating the noise, thereby providing an estimated noise;
• (b) bandpassing the received signal in a plurality of adjacent pass bands to obtain a corresponding plurality of signal subbands;
• (c) bandpassing the estimated noise in said plurality of adjacent pass bands to obtain a corresponding plurality of noise subbands;
• (d) for each said signal subband:
• (i) obtaining a power measure of said each signal subband,
• (ii) comparing said power measure of said each signal subband to said power measure of at least one other signal subband, and
• (iii) whenever
• said power measure of said at least one other signal subband exceeds said power measure of said each signal subband by a signal masking threshold,
• nulling said each signal subband,
• otherwise,
• adjusting said each signal subband so that said each signal subband masks a corresponding said noise subband,
• (e) detecting an onset of the transmitted signal;
• and
• (f) upon detection of said onset, inhibiting said bandpassing of the received signal,
• wherein said inhibiting is continued until said power of the signal decreases below an end-of-transmission power threshold at a rate exceeding an end-of-transmission rate threshold.