Continuous frequency dynamic range audio compressor

A continuous frequency dynamic range compressor comprising:

• a filter bank including a plurality of filters for filtering an input signal into a plurality of frequency bands;
• a plurality of power estimators, each power estimator connected to a filter, each power estimator for estimating the power in the frequency band of its associated filter and generating a power signal related to the power in the frequency band of its associated filter;
• a plurality of gain calculators, each gain calculator connected to a power estimator, each gain calculator for calculating a gain related to the power estimated by its associated power estimator;
• a plurality of gain applying means, each gain applying means connected to a gain calculator, each gain applying means for applying the gain calculated by its associated gain calculator to the frequency band associated with its associated gain calculator;
• and
• means for summing the gain-applied frequency bands;
• wherein said filters filter the input signal into sufficiently heavily overlapped frequency bands to reduce the ripple in the frequency response, given a slowly swept sine wave input signal and a compression ratio of at least about 4, to below about 2 dB.

A continuous frequency dynamic range compressor comprising:

• a filter bank including a plurality of filters for filtering an input signal into a plurality of frequency bands;
• a plurality of power estimators, each power estimator connected to a filter, each power estimator for estimating the power in the frequency band of its associated filter and generating a power signal related to the power in the frequency band of its associated filter;
• a plurality of gain calculators, each gain calculator connected to a power estimator, each gain calculator for calculating a gain related to the power estimated by its associated power estimator;
• a plurality of gain applying means, each gain applying means connected to a gain calculator, each gain applying means for applying the gain calculated by its associated gain calculator to the frequency band associated with its associated gain calculator;
• and
• means for summing the gain-applied frequency bands;
• wherein said filters filter the input signal into sufficiently heavily overlapped frequency bands to reduce the ripple in the frequency response, given a slowly swept sine wave input signal and a compression ratio of between about 1.5 and about 4, to below about 1 dB.

A hearing aid comprising:

• a microphone for detecting sound and generating an electrical signal relating to the detected sound;
• an analog to digital converter for converting the electrical signal into a digital signal;
• means for digitally processing the digital signal;
• a digital to analog converter for converting the processed digital signal to a processed analog signal;
• and
• means for converting the processed analog signal into a processed sound signal;
• wherein the digital processing means includes a continuous frequency dynamic range compressor including:
• a filter bank including a plurality of filters for filtering the digital signal into a plurality of frequency bands;
• a plurality of power estimators, each power estimator connected to a filter, each power estimator for estimating the power in the frequency band of its associated filter and generating a power signal related to the power in the frequency band of its associated filter;
• a plurality of gain calculators, each gain calculator connected to a power estimator, each gain calculator for calculating a gain related to the power estimated by its associated power estimator;
• a plurality of gain applying means, each gain applying means connected to a gain calculator, each gain applying means for applying the gain calculated by its associated gain calculator to the frequency band associated with its associated gain calculator;
• and
• means for summing the gain-applied frequency bands;
• wherein said filters filter the input signal into sufficiently heavily overlapped frequency bands to reduce the ripple in the frequency response of the filter bank, given a slowly swept sine wave input signal, to less than 2 dB.