Speech perception abilities of single-sided deaf adult cochlear implant users; normal hearing ear and cochlear implanted ear.

Abstract

Background: Single-sided deaf patients have one normal hearing ear and one ear with moderate to profound hearing loss. Single-sided deafness can result in two main difficulties; problems with localization and speech perception. Up until recently, a criterion for a cochlear implant was bilateral hearing loss. It is, still, difficult to predict the speech perception abilities of a single-sided deaf adult with a cochlear implant. Aim: The aim was to find a test which provides an accurate prognosis of speech perception in adult single-sided cochlear implant users. Method: This observational, correlational, cross-sectional study included 18 adults. The participants performed hearing in noise tests, a spectral resolution test, a vocabulary test, and a working memory test. A comparison of the mean group data is reported. Also reported are correlations between the tests and the context factors. Results: The participants performed significantly better with their normal hearing ear compared to their cochlear implanted ear. The context factors j and k did not significantly differ. Significant high correlations were found between phonological processing and hearing in noise for the implanted ear and lexical context factor j. Significant moderate correlations were found between spectral resolution for the normal hearing ear and both the j factor for phonemes in a word and the k factor for the implanted ear. A significant low correlation was found between the k factor of the implanted ear and a hearing in noise result for the normal hearing ear. Conclusion and Recommendations: The results put phonological processing forward as a predictor for future performance in speech perception for single-sided deaf adults with a cochlear implant. It is, however, noteworthy that this study lacks power. Future research should include more participants and divide these participants up into subgroups.