Sound lateralization ability of patients with bilateral microtia and atresia after bilateral reconstruction of auricles and external auditory canals and fitting of new canal-type hearing aids to replace a bone conduction hearing aid.
CONCLUSIONS
Each of eight patients with bilateral microtia and atresia underwent bilateral reconstruction of the auricles and external auditory canals and were fitted bilateral canal-type hearing aids in the operated ears to replace a bone conduction hearing aid. The ability to discriminate inter-aural intensity difference (IID) and even inter-aural time difference (ITD) was retained in all these patients.


OBJECTIVE
This study studied the post-operative sound lateralization ability of patients with bilateral microtia and atresia after total reconstruction of both auricles and external auditory canals, followed by fitting of bilateral canal-type hearing aids.


METHODS
Eight patients with bilateral microtia and atresia ranging in age from 13-43 years were recruited in this study. Each of them underwent bilateral reconstruction of the auricles and external auditory canals and were fitted canal-type hearing aids in both the operated ears to replace a bone conduction hearing aid. A sound lateralization test was conducted to determine IID and ITD discrimination ability thresholds.


RESULTS
In all the patients, the IID discrimination ability thresholds of the patients were more than 3-fold those of the controls, the ITD discrimination ability threshold was more than 5-fold those of controls, and binaural hearing was retained.
a National Institute of Sensory Organs , National Tokyo Medical Center , Tokyo , Japan.
Kimitaka
K
Kaga
b Department of Plastic Surgery , Dokkyo Medical University , Tochigi , Japan.
Hirotaka
H
Asato
D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D065817:Congenital Microtia / Q000601:surgery*; D004424:Ear Canal / Q000002:abnormalities / Q000601:surgery*; D005260:Female; D006310:Hearing Aids; D006801:Humans; D008297:Male; D019651:Plastic Surgery Procedures; D013017:Sound Localization; D055815:Young Adult
Binaural hearing; air conduction; bone conduction; inter-aural intensity difference; inter-aural time difference