James F. Maurer

Date of Award


Document Type


Degree Name

Master of Science (M.S.) in Speech Communication


Speech Communication

Physical Description

1 online resource (91 p.)


Audiometry, Hearing aids -- Evaluation




These two joint-studies used recorded versions of the Northwestern University Auditory Test Number 6 (NU-6) and the California Consonant Test (CCT) in the hearing aid evaluations (HAEs) of 12 male and one female subjects, aged 41 to 87 years. They exhibited precipitous high frequency losses beyond 1 kHz in at least one ear. All subjects were evaluated without amplification and while monaurally aided with two conventional high pass hearing aids. Ten of the subjects were evaluated in multi-talker noise and 11 were tested in quiet. Since the CCT was more heavily weighted than the NU-6 with target phonemes sensitive to high frequency losses, it was hypothesized that the CCT might be more sensitive than the NU-6 to significant differences between aided and/or unaided performances of these particularly high frequency impaired subjects.

The data collected in noise and in quiet was analyzed separately with the one-way analysis of variance (ANOVA) for repeated measures. No significant differences were found in noise or quiet between the aided performances on either the CCT or the NU-6. The NU-6 in noise, however, revealed significant degrees of aided improvement at the .01 level of confidence that the CCT did not. The addition of noise seemed to make the CCT too difficult for these subjects. In quiet, both tests seemed to be as equally sensitive in revealing significant aided improvement at the .01 level of confidence. The lower mean CCT scores in quiet, however, seemed to indicate that if unaided NU-6 performances are too high to allow for significant aided improvement or significant differences between aids, the more time consuming CCT might be appropriate.


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