Interaural attenuation for pure tones and speech.

Abstract

In air conduction audiometry, both pure tone and speech, a problem arises when testing persons with unilateral or substantial bilateral asymmetrical hearing losses because signals of high intensity in the worse ear travel through the skull and stimulate the non-test (better) cochlea. Response by the non-test ear is eliminated by the introduction of a masking noise, but, in order to know when this is necessary and what level of masking is required for a particular signal level, the interaural attenuation of the signal, be it pure tone or speech, for the particular apparatus used must be known.In this study the interaural attenuation for pure tones of 250 Hz to 4 kHz and for Arthur Boothroyd's (AB) isophonemic word lists delivered via TDH-39 receivers in MX41/AR cushions were determined in 11 subjects with unilateral hearing losses. Measuring the ineraural attanuation for pure tones as the difference between the air conduction threshold of the good ear and the shadow threshold measured in the poor ear gave ...