Sound lateralization test in patients with unilateral microtia and atresia after reconstruction of the auricle and external canal and fitting of canal-type hearing aids

CONCLUSION: In patients with unilateral microtia and atresia after reconstruction of the auricle and external canal and fitting of a canal-type hearing aid for the operated ear, the ability to discriminate the inter-aural intensity difference (IID) was acquired in all of the patients, whereas that to discriminate inter-aural time difference (ITD) was acquired in one-half of the patients. OBJECTIVE: To study the post-operative sound lateralization ability in patients with unilateral microtia and atresia after reconstruction surgery of the auricle and external canal and fitting of a canal-type hearing aid of the operated ear. METHODS: Eighteen patients with unilateral microtia and atresia ranging from 13-24 years of age were recruited in this study. All of them underwent reconstruction of the auricle and external canal and were fitted a canal-type hearing aid for the operated ear. The sound lateralization test was conducted to determine IID and ITD using a self-recording apparatus. The test stimulus was a continuous narrow-band noise at 500 Hz and 50 dBHL presented to the right and left ears through the air conduction receivers. RESULTS: IID could be measured in all of the patients, whereas ITD could be measured in only nine out of the 18 patients. Post-operative binaural hearing could be acquired in all the patients.