Cochlear implants better than hearing aids, bone conduction device in single-sided deafness

Cochlear implants (CI) outperform contralateral routing of sound hearing aids (CROS) and bone conduction devices (BCD) for improving sound perception in individuals with single-sided deafness (SSD), according to a recent study.

“Speech perception in noise improved in all configurations for the CI group, whereas speech perception in noise improved or deteriorated for the BCD and CROS groups depending on the configuration. Sound localization improved in the CI group only,” the researchers said. Nevertheless, “in general, all treatment options improved disease-specific quality of life (QoL) on most subscales of the used questionnaires.”

The study included 113 patients with SSD who were randomized to receive CI (n=28), BCD (n=25), CROS (n=34), or no intervention (n=26). Baseline characteristics were comparable across arms.

At the 3- and 6-month follow-up sessions, patients given CI showed significant improvements in speech perception in noise, with both sounds coming from the front. In comparison, such perception also improved in patients with BCDs, but only after 6 months. The CROS and no-treatment arms saw no such changes. [PLoS One 2021;16:e0257447]

Comparing across groups per time point, the researchers found that at 3 months, CI participants significantly outperformed all other groups in terms of sound perception in noise (both coming from the front). The advantage of CI over BCD and no treatment, but not CROS, remained significant until 6 months.

Moreover, when speech was directed at the better ear while noise at the poor ear, CI continued to yield significant improvements in perception at both 3 and 6 months. Meanwhile, patients in the BCD and CROS arms deteriorated significantly. Comparatively, CI performed significantly better than BCD and CROS at all time points in this sound scenario.

In terms of tinnitus, CI and BCD led to significant declines in related distress at months 3 and 6 relative to baseline. At all time points, CI elicited significantly lower tinnitus questionnaire scores than the no-intervention controls. The impact of tinnitus on daily life likewise significantly declined at 3 and 6 months in the CI group.

Such improvements in speech perception and tinnitus led to better disease-specific QoL, with CI patients showing better scores in tools assessing speech-hearing, spatial hearing, qualities of hearing, ease of communication, background noise, and aversiveness of sounds, among others, at both follow-ups. Health status after otorhinolaryngological procedures (as per the Glasgow Benefit Inventory) was likewise improved in the CI group.

Disease-specific QoL improvements were also detected for CROS and BCD, though to generally lesser degrees than in the CI arm.

“Aside from the reported outcome measures, which show the individual benefits, analysis of the costs of the treatment options is necessary to reveal societal benefits,” the researchers said. “This information will allow healthcare committees to perform a cost utility analysis, which will help in the consideration whether or not to reimburse cochlear implantation for patients with SSD.”