Frequency response analyzer and shaping apparatus and digital hearing enhancement apparatus and method utilizing the same

A signal frequency analyzer and frequency response shaping apparatus using digital techniques and apparatus and methods using the same which is applicable, in one embodiment thereof, to the enhancement of hearing in hearing impaired persons. Analog techniques are used in another embodiment of the invention. The invention includes hearing enhancement apparatus and methods which employ digital transformation, processing and memory functions for performing a wide range of hearing enhancement functions including the control of instantaneous signal gain levels as a function of instantaneous frequency and amplitude values of an audio signal. In another embodiment, the invention is applicable as a simple and inexpensive frequency analyzer which provides many of the characteristics of a complete Fast Fourier Transform (FFT) suitable for audio signals and other signals where a lower resolution FFT equivalent is acceptable.