Improved hearing procedures with broadband compression

Procedures were investigated which led to a shift of the spectrum. As a result the essential spectral parts for speech understanding which are not perceptible for the hard of hearing are transposed into the hearing region which remains. Persons with normal hearing and hard of hearing were subjected to loudness-confusion tests and both have benefited from superimposed speech simulating noises with different transposition methods. The minimal confusion frequency arises from the frequency reproduction characteristic which allows entanglement without evaluation of the fundamental speech frequency. A proposal for the realisation of a transposition hearing-aid is set out.