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.