Clinical hearing-loss diagnoses rest on subjective psychoacoustic data because human neurophysiology is rarely available.

Evidence

Neurophysiological data concerning signal processing in hearing stem almost exclusively from animals. Only from very rare operations is it possible to collect data from human beings. l\lost of the psychoacoustical data, however, stem from subjectively measured human data. Therefore, most decisions regarding the type of disease in hearing-impaired subjects are based on psychoacoustical data. although objective results might be more useful. Therefore, the purely physically measured otoacoustic emissions seem to be an attractive tool for obtaining information about signal processing in the human inner ear. The problem. however, is that otoacoustic emissions seem to be produced only in subjects who have a hearing loss no greater than about 20 dB. Out of more than 200 students in a school for the hearing-impaired. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1871

Categorization

• QUESTION: Why does objective animal neurophysiology not transfer cleanly to human diagnosis? The passage gestures at this gap without fully explaining it.