Abstract: An apparatus and technique for enhancing the hearing capabilities of persons by providing a device which is a model of the desired hearing characteristic of the persons.

Abstract: An adaptive noise suppressor for providing noise filtered signals. The noise suppression device employs a vector gain .mu. for the weights of the filter wherein the vector .mu. is selected for each frequency bin to be inversely proportional to the power spectrum. A projection operator is utilized to remove the effects of circular convolution to produce a linear convolution result wherein the weights are readjusted in a manner to minimize the difference between the input signal and the filter output signal, thereby minimizing the error signal to produce a noise suppressed signal in the filtered output. A frequency suppression device utilizes the same principles of the vector .mu. and projection operator, but the output is taken from the error output of the filter.