Speech Perception Outcomes in Transcutaneous Versus Percutaneous Bone Conduction Stimulation in Individuals With Single-sided Deafness

Objective(s): To investigate the differences in percutaneous versus passive transcutaneous bone-conduction stimulation in individuals with single-sided deafness. Study Design: Prospective, single-subject. Setting: Tertiary academic referral center. Patients: Adult bone-anchored implant listeners with single-sided deafness using a percutaneous implant system. Interventions: Experienced percutaneous bone anchored implant recipients were tested in the percutaneous and transcutaneous conditions using a BAHA 5 (Cochlear Corp., Cochlear Bone-Anchored Solutions, Molnlycke, Sweden) sound processor on the patient's own abutment and on a softband. Main Outcome Measures: Phoneme recognition was assessed using Consonant-Nucleus-Consonant (CNC) words for soft (47 dB SPL) and average (62 dB SPL) speech inputs. Speech perception in noise performance was also assessed for soft (47 dB SPL) and average (62 dB SPL) speech inputs using sentences presented in multi-talker babble. Aided free-field thresholds were obtained in both conditions using warble tone stimuli. Results: Compared with percutaneous bone-conduction stimulation, transcutaneous stimulation demonstrated reduced effective gain for high frequency stimulation. Transcutaneous stimulation required higher signal to noise ratios to achieve comparable performance to the percutaneous condition. Phoneme recognition was poorer in transcutaneous versus percutaneous stimulation with the most significant impact observed for soft speech inputs. Conclusion: A significant performance gap in speech recognition is observed between percutaneous and transcutaneous bone-conduction stimulation in individuals with single-sided deafness at the same signal to noise ratios. Compared with percutaneous bone-conduction stimulation, transcutaneous stimulation demonstrated reduced effective gain, decreased phoneme recognition, word recognition, and performance in noise, with the most significant impact observed for soft speech inputs.