Transcranial Attenuation in Patients with Single-Sided Deafness.

Transcranial attenuation (TA) of bone-conducted sound has a high degree of variability by frequency and subject, which may play a role in the objective benefit of individuals with single-sided deafness (SSD) treated with a bone-anchored implant (BAI). This study sought to determine whether TA is predictive of benefit in individuals with SSD who receive a BAI. Adult, English-speaking patients with unilateral profound sensorineural hearing loss who underwent a BAI evaluation were included for study. Absolute TA values were consistent with previously published reports. Regression analysis indicated no correlation between TA values and aided speech-in-noise performance for any combined or individual frequencies. Measures of TA do not provide predictive value in determining behavioral outcomes in the SSD population. Specifically, low TA does not suggest improved outcomes with a BAI.

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, Mölnlycke, 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.