The benefit of binaural hearing aids: prognostic test and evaluation.

Introduction. As part of a national study on the practice and effectiveness of binaural hearing aid fitting, we developed two sets of tests. The first set of tests, using headphones, is a diagnostic tool and aims at measuring hearing abilities that are needed to obtain benefit from a binaural hearing aid. The second set of tests, using loudspeakers, aims at an evaluation of the obtained benefit in speech perception and localization in everyday conditions. Methods. Tests were conducted with candidates for binaural hearing aid fitting. Prognostic tests included binaural masking level difference, detection of interaural time delay, detection of a spectral notch and the precedence effect. The evaluation was performed with tests on speech reception with modulated noise or several interfering talkers in different configurations. Additionally, the hearing aid benefit was evaluated with a dedicated questionnaire measuring subjective improvement in auditory performance. Results. Thus far, the tests have been completed for 13 patients; only one of them eventually preferred a monaural hearing aid. Results on the evaluation tests are in accordance with the results of the questionnaire. The number of patients is still too low to establish the value of prognostic tests. Larger numbers will be available at the meeting. [ABSTRACT FROM AUTHOR]