Functional Result After Cochlear Implantation in Children and Adults With Single-sided Deafness

Patients with single-sided deafness (SSD) suffer from reduced binaural hearing (i.e., sound localization and speech in noise discrimination). Cochlear implantation has recently been introduced for patients with SSD, as an alternative to hearing devices that employ contralateral routing of the signal. Application to children has also been started.

We retrospectively analyze a case series of 4 children and 17 adults with SSD, treated with cochlear implantation. The outcome of adult patients was compared with a control group of 27 patients with bilateral profound hearing loss using a cochlear implant.

During 12 months, the mean speech recognition score increased from 30 to 41% for monosyllabic words in adults, and from 58 to 89% for multisyllabic numbers. The cochlear implant (CI) improved hearing in noise in all SSD patients, as was demonstrated by a significant improvement of the speech reception threshold in different speech and noise configurations. Sound localization-correlated angle detection error improved with CI use at every time point. The maximum word recognition score for monosyllabic words in quiet correlated with the logarithm of the duration of deafness; improvement of the speech reception threshold and RMS angle detection error by the CI did not.

All SSD patients benefitted from the CI in different hearing situations. Patients with SSD for a long period can improve after cochlear implantation.