A method is described for determining the frequency response curve or characteristic to be incorporated into sound amplification apparatus utilized by aurally handicapped persons. An auditory threshold is first determined as a function of frequency utilizing pink or white noise passed through 1/3 octave bandpass filters. Subsequently, comfort level response is determined (in the same manner) with the loudness increased for each nominal frequency band until the patient indicates distinct discomfort, the loudness being then decreased until the patient considers the level to be comfortable. Examination of the curves thus obtained may reveal one or more 1/3 octave frequency bands at which dynamic range, the difference between the threshold and comfort levels, is abnormally reduced. Playback apparatus is then adjusted generally to conform to the comfort level curve. Preferably, these tests and the playback apparatus comprehend a broad frequency range on the order of 100 hz to 10 kHz. The adjustment of the playback apparatus may subsequently be altered in accordance with predetermined principles in order to enhance the aurally handicapped person's capacity to understand the spoken language.
METHOD AND APPARATUS FOR PROVIDING ELECTRONIC SOUND CLARIFICATION FOR AURALLY HANDICAPPED PERSONS