A method and device for processing signals representing speech or audio via a plurality of filters that approximate behaviors of the basilar membrane of human cochlea. Each of the plurality of filters is formed from a mother filter via the dilation and a shift in time and has the similar impulse response of the basilar membrane to the frequency band for which the filter represents. Any process can be conducted and any feature can be extracted in the domain of the filters' outputs for applications, such as noise reduction, speech synthesis, coding, and speech and speaker recognition. Processed signals can be synthesized back to the time domain via an inverse cochlear transform.