[Comparison of audiological performance bewteen bone-anchored and conventional hearing aids]

The bone-anchored hearing aid (BAHA) is an implantable bone-conduction device that vibrates the skull directly via a surgically implanted titanium screw behind the ear. The BAHA has advantages for patients with aural atresia or chronic ear drainage, who cannot wear air-conduction hearing aids. We compared the function of BAHA to conventional bone and air-conduction hearing aids based on functional gain and speech discrimination tests in quiet and noisy environments in 2 patients with chronic ear problems. All expressed a clear preference for the BAHA over conventional bone-conduction hearing aids. The BAHA and air-conduction hearing aid provided similar audiological performance when the functional gain of each hearing aid coincided. As the air-bone gap widens, however, audiological performance with the BAHA showed an evident preference, indicating that the width of the air-bone gap is of some help in BAHA preference compared to air-conduction hearing aids.