Abstract: An overview about the mechanism of transducer, amplification and frequency selection of hearing and the advantage of using Bark as a unit for frequency scale, is given.
New results about the sensation of combination tone in relation with the nonlinearity of the transducer action, the phase effect and inner spectrum, the existance of Kemp echo, physiological amplifier and a time window for spectral analysis are reviewed.
Phenomenum of hearing loss, in particular, the auditory recruitment due to acoustic traum of intensive sound, works done in improving performance of hearing aid and perspective of implementing new hearing aid device with the achievements of microelectronics are briefly disseused.
The experience of using MTF as a criterion evaluating sound quality in rooms and novel works done on high fidelity stereophonic sound transmission with binaural corsstalk compensation and artificial lateral reflection are reported.