Method and apparatus for automatic non-cooperative frequency specific assessment of hearing impairment and fitting of hearing aids

A method for automatically assessing loss of hearing sensitivity and loss of compression with user defined frequency resolution by means of extrapolated Otoacoustic Emission Input/Output functions (OAE I/O-functions) and Auditory Brain Stem Responses (ABRs) as well as for automatically fitting hearing aids comprising:

• generating one or more acoustic stimuli in the subject's ear canal by means of a sound probe, wherein the sound probe further comprises a sound probe seal, and an acoustic stimuli generator, recording any Transient Evoked Otoacoustic Emissions (TEOAEs) and Distortion Product Otoacoustic Emissions (DPOAEs) generated by the cochlea in the subject's ear canal in response to the acoustic stimuli by collector means, inputting the collector means′ output-signal into a signal processor, calibrating the acoustic stimuli in the ear canal by checking the sound probe's seal and estimating sound pressure proximate the eardrum by generating a defined stimulus level signal in front of the eardrum, analysing amplitude, phase, and frequency of cochlear responses, evaluating the responses and signals by binominal statistics or signal-to-noise estimates to determine whether the measured signals contain stimulus correlated components on a defined level of significance, estimating the cochlear responses at threshold as well as at stimulus levels higher than applied by extrapolating cochlear responses that are generated within the dynamic range of the acoustic stimulation, converting the estimated stimulus levels at threshold into hearing loss levels and reconstructing a clinical audiogram for display, and estimating cochlear compression from extrapolated OAE I/O-functions for providing the gain of hearing aid needed to provide subject's normal hearing.