Abstract: A hearing aid device providing instantaneous gain compression for sound signals and adaptive control of nonlinear waveform distortion, the device comprising: (a) at least one bandpass nonlinearity (BPNL) amplifier comprising a first bandpass filter, a second bandpass filter, and a memoryless nonlinear (MNL) compressive audio amplifier configured to receive a sound signal from the first bandpass filter and provide an MNL compressive audio amplifier output to the second bandpass filter, wherein the MNL compressive audio amplifier is configured to produce the MNL compressive audio amplifier output by providing memoryless gain compression directly on a sound signal that is (1) received from the first bandpass filter and (2) exhibits instantaneous amplitudes greater than a compression threshold, the BPNL amplifier thereby producing a desired gain compression on the received sound signal at an output of the second bandpass filter, and (b) a controller in communication with the BPNL amplifier, the controller being c

Abstract: Methods and devices for audio amplification suitable for hearing aid, hearing aid fitting, and diagnostic purposes include audio amplification having at least one variable gain channel configured to provide relatively higher gain at low levels, rapid gain compression at intermediate levels converging to linear gain at high signal levels, and slow feedback control of the compressive gain. Several such audio channels may be provided in a hearing aid or diagnostic device, and instantaneous gain compression is preferred. An analog implementation provides nonlinear elements in a feedback path to simulate a multiple feedback band-pass non-linearity cochlear filterbank hearing model (MFBPNL), while a digital implementation uses logarithmic representations of signals to minimize functional components in a multiple band-pass non-linearity cochlear filterbank hearing model (MBPNL). When used as a hearing aid, annoying amplification of weak sounds during brief interruptions of sustained intense sounds is prevented.

Abstract: In a hearing amplification device adapted to receive a sound signal, the hearing amplification device having at least one channel configured to receive an input representative of said sound signal, the improvement comprising the channel being further configured to provide (1) linear gain for an input representative of a portion of the sound signal having a sound level less than a compression threshold, (2) rapid compressive gain for an input representative of a portion of the sound signal having a sound level greater than the compression threshold, wherein the rapid compressive gain is less than the linear gain, and (3) adaptive control of the compression threshold. Preferably the rapid compressive gain is instantaneous. Adaptive compression threshold control may be achieved in response to a user input and/or to sound signal changes. By adaptively controlling the compression threshold, performance of the device can be optimized to match its environment.

Abstract: A model simulating cochlear spectrum analysis is disclosed which includes a pair of matched all pole lattices interconnected by a plurality of tip couplers providing non-linear distributed bilateral signal processing. One of the lattices along with the tip couplers corresponds to the organ of Corti found in the cochlea and the second lattice corresponds to the basilar membrane also found in the cochlea such that the model provides a striking resemblance in structure to the physical properties of the cochlea itself. With the cochlea model disclosed, distortion products and otoacoustic emissions are simulated. An intermediate model is also disclosed which provides bilateral signal processing but lacks distributed amplification.