Review: Bone conduction devices and contralateral routing of sound systems in single‐sided deafness

OBJECTIVES/HYPOTHESIS: Systematically review the literature on the clinical outcome of bone conduction devices (BCD) and contralateral routing of sound systems (CROSS) for patients with single-sided deafness (SSD). DATA SOURCES: PubMed, Embase, Cochrane Library, and CINAHL databases were searched up to April 7, 2014. REVIEW METHODS: All studies investigating BCD and CROSS for patients with SSD on speech perception in noise, sound localization, or quality of life were selected and critically appraised. RESULTS: In total, 46 articles were retrieved, of which six satisfied the eligibility criteria. Critical appraisal showed that five studies (n = 91) carried a moderate to high directness of evidence and a low to moderate risk of bias. Subsequently, study characteristics and outcome measurements were extracted. Due to large heterogeneity between studies, pooling of data was not feasible. Studies did not show a clear advantage of BCD or CROSS on speech perception in noise. BCD and CROSS lead to the same sound localization ability as the unaided condition. Quality of life did not differ significantly between conditions; however, subjective speech communication did improve. CONCLUSION: No high level of evidence studies compare BCD and CROSS in patients with SSD. Literature showed no beneficial effect of BCD or CROSS regarding speech perception in noise and sound localization. Subjective speech communication demonstrated a moderate improvement with BCD and CROSS. High evidence studies comparing all treatment options for single-sided deafness should be conducted.