Impact of Hearing Loss and Amplification on Performance on a Cognitive Screening Test.

BACKGROUND: There have been numerous recent reports on the association between hearing impairment and cognitive function, such that the cognition of adults with hearing loss is poorer relative to the cognition of adults with normal hearing (NH), even when amplification is used. However, it is not clear the extent to which this is testing artifact due to the individual with hearing loss being unable to accurately hear the test stimuli. PURPOSE: The primary purpose of this study was to examine whether use of amplification during cognitive screening with the Montreal Cognitive Assessment (MoCA) improves performance on the MoCA. Secondarily, we investigated the effects of hearing ability on MoCA performance, by comparing the performance of individuals with and without hearing impairment. STUDY SAMPLE: Participants were 42 individuals with hearing impairment and 19 individuals with NH. Of the individuals with hearing impairment, 22 routinely used hearing aids; 20 did not use hearing aids. DATA COLLECTION AND ANALYSIS: Following a written informec consent process, all participants completed pure tone audiometry, speech testing in quiet (Maryland consonant-nucleus-consonant [CNC] words) and in noise (Quick Speech in Noise [QuickSIN] test), and the MoCA. The speech testing and MoCA were completed twice. Individuals with hearing impairment completed testing once unaided and once with amplification, whereas individuals with NH completed unaided testing twice. RESULTS: The individuals with hearing impairment performed significantly less well on the MoCA than those without hearing impairment for unaided testing, and the use of amplification did not significantly change performance. This is despite the finding that amplification significantly improved the performance of the hearing aid users on the measures of speech in quiet and speech in noise. Furthermore, there were strong correlations between MoCA score and the four frequency pure tone average, Maryland CNC score and QuickSIN, which remain moderate to strong when the analyses were adjusted for age. CONCLUSIONS: It is concluded that the individuals with hearing loss here performed less well on the MoCA than individuals with NH and that the use of amplification did not compensate for this performance deficit. Nonetheless, this should not be taken to suggest the use of amplification during testing is unnecessary because it might be that other unmeasured factors, such as effort required to perform or fatigue, were decreased with the use of amplification.

Word Recognition and Learning: Effects of Hearing Loss and Amplification Feature.

Two amplification features were examined using auditory tasks that varied in stimulus familiarity. It was expected that the benefits of certain amplification features would increase as the familiarity with the stimuli decreased. A total of 20 children and 15 adults with normal hearing as well as 21 children and 17 adults with mild to severe hearing loss participated. Three models of ear-level devices were selected based on the quality of the high-frequency amplification or the digital noise reduction (DNR) they provided. The devices were fitted to each participant and used during testing only. Participants completed three tasks: (a) word recognition, (b) repetition and lexical decision of real and nonsense words, and (c) novel word learning. Performance improved significantly with amplification for both the children and the adults with hearing loss. Performance improved further with wideband amplification for the children more than for the adults. In steady-state noise and multitalker babble, performance decreased for both groups with little to no benefit from amplification or from the use of DNR. When compared with the listeners with normal hearing, significantly poorer performance was observed for both the children and adults with hearing loss on all tasks with few exceptions. Finally, analysis of across-task performance confirmed the hypothesis that benefit increased as the familiarity of the stimuli decreased for wideband amplification but not for DNR. However, users who prefer DNR for listening comfort are not likely to jeopardize their ability to detect and learn new information when using this feature.

Detecting and Learning New Words: The Impact of Advancing Age and Hearing Loss.

PURPOSE: Lexical acquisition was examined in children and adults to determine if the skills needed to detect and learn new words are retained in the adult years. In addition to advancing age, the effects of hearing loss were also examined. METHOD: Measures of word recognition, detection of nonsense words within sentences, and novel word learning were obtained in quiet for 20 children with normal hearing and 21 with hearing loss (8-12 years) as well as for 15 adults with normal hearing and 17 with hearing loss (58-79 years). Listeners with hearing loss were tested with and without high-frequency acoustic energy to identify the type of amplification (narrowband, wideband, or frequency lowering) that yielded optimal performance. RESULTS: No differences were observed between the adults and children with normal hearing except for the adults' better nonsense word detection. The poorest performance was observed for the listeners with hearing loss in the unaided condition. Performance improved significantly with amplification to levels at or near that of their counterparts with normal hearing. With amplification, the adults performed as well as the children on all tasks except for word recognition. CONCLUSIONS: Adults retain the skills necessary for lexical acquisition regardless of hearing status. However, uncorrected hearing loss nearly eliminates these skills.