Assessment of discrimination ability in ipsilateral and contralateral ears with a unilateral bone-anchored hearing system.

This study aimed to determine the speech discriminatory ability of the contralateral ear of users of a unilateral bone-anchored hearing system (BAHS). The Oticon Medical Ponto Pro/Ponto Pro Power device brand was used for all patients. Five BAHS users (3 men, 2 women) participated in the study. Pure-tone air-conduction thresholds at 250 to 6,000 Hz, masked and unmasked bone-conduction thresholds at 250 to 4,000 Hz, and participants' speech discrimination scores in both ears were determined. Speech discrimination tests were carried out in a silent environment with monosyllabic and trisyllabic word lists. After this, the ipsilateral ear (the BAHS side) was masked with wide-band noise using an insert earphone, and the word tests were repeated. A mild decrease was observed in monosyllabic words in ipsilateral masking; however, this was not found to be statistically significant. Conversely, a decrease was not observed in the repetition of trisyllabic words in any participants, even under high-level ipsilateral masking. These results suggested that unilateral BAHS application could prevent or reduce the neural deprivation of the contralateral ear.