Subjective comparisons of binaural versus monaural amplification.

Patient preference for monaural versus binaural hearing aids was studied to evaluate the subjective differences noted between these two types of fittings. Subjects were 30 patients with bilateral hearing impairment who were being fit with amplification for the first time. Subjects wore both monaural and binaural hearing aids for controlled periods of 1 hr each and 2 days each. This was followed by an additional 3 days during which the fittings were alternated at the subjects' own discretion. Subjects reported preferences and subjective differences after each experimental phase. Interviews were conducted 3 months after participation in the study to determine actual hearing aid use. Binaural amplification was preferred by 90% of the subjects for consistently similar reasons. Results also suggest that consistency of preferences throughout an initial trial period may be predictive of successful adjustment to and use of amplification. Findings indicate that the routine practice of fitting monaural hearing aids may not provide optimum fittings for many patients.

The reliability and validity of the comfort level method of setting hearing aid gain.

The comfort level method (Carhart, 1946) probably is the most widely used procedure for setting the acoustic gain of hearing aids. A series of experiments were conducted to determine the test-retest reliability of the comfort level method and the relationship between the comfort settings established in a clinical test suite and the comfort settings utilized in more realistic daily listening situations. Adults with bilateral sensorineural hearing impairments were subjects. The results suggest that the comfort level method has good test-retest reliability for most clinical purposes. Further, clinically established comfort settings may accurately represent typical daily-use settings if the input level used to establish the comfort settings in the clinical environment is 70 dB SPL.