BKB-SIN and ANL predict perceived communication ability in cochlear implant users

Cochlear implant (CI) users typically report that speech recognition becomes substantially more difficult in the presence of background noise. This perception is consistent with objective measures of speech recognition showing that CI users require more favorable signal-to-noise ratios than normal-hearing (NH) listeners to achieve equivalent speech recognition. However, recent research in hearing aid users suggests that noise tolerance or the "willingness to listen in noise" may also influence perceived communication ability. Therefore, the purpose of this study was to evaluate the extent to which speech recognition in noise and noise tolerance predict perceived communication ability among adult CI users.

Twenty adult CI users were evaluated on an objective test of speech recognition in noise (Bamford-Kowal-Bench Sentences in Noise [BKB-SIN] test) and a measure of noise tolerance (Acceptable Noise Level [ANL] test) and completed a self-report measure of communication difficulty (Abbreviated Profile of Hearing Aid Benefit [APHAB]). Relationships between BKB-SIN scores, ANL scores, and aided APHAB scores for the ease of communication, background noise, reverberation, and Global scales were assessed. In addition, BKB-SIN scores and ANL scores for the CI users were compared with scores for a control group of 23 NH listeners.

CI users demonstrated substantially poorer BKB-SIN scores than NH listeners, as expected; however, their ANL scores were similar to those for NH listeners. BKB-SIN scores and ANL scores were not systematically related to one another. Each measure accounted for more than one third of the variance in CI users' aided APHAB Global scores; together, the two measures accounted for 72% of that variance.

Both speech recognition in noise and noise tolerance are strongly associated with CI users' self-perceived communication ability. The two measures seem to reflect different factors that influence an individual's communication experience; thus, both may provide useful clinical information. The establishment of formal criteria for BKB-SIN scores and ANL scores that are predictive of excessive communication difficulty may help to identify CI users who could benefit from additional audiologic rehabilitation.