2.4 Outcome Measures
After three months post-fitting, four main outcomes were administered: (1) the time for wearing a hearing aid, (2) the hearing in noise test (HINT)), (3) sound localization test, and (4) the Korean version of the International Outcome Inventory for Hearing Aids (IOI-HA). The time for wearing a hearing aid was investigated using IOI-HA as well as data-logging. The HINT and sound localization were performed in unaided and aided conditions. The HINT was performed with 50 recorded Korean monosyllables were presented using presentation levels from 40 dB in 5-dB steps at a 1-meter distance in the sound-field while speech spectrum noise was presented with a fixed intensity at SNR 0 dB. Aided-unaided difference in speech discrimination score of more than 2% was a criteria of meaningful difference. Sound localization test was performed with spondee were presented at a fixed level of 50 dB at a 1-meter in azimuth of the front, right, and left sides in the sound-field while the presented azimuth was randomly selected and the speech was presented during 5 seconds with a silent interval of 5 seconds. The examinee answered the direction of a sound source. If the examinee answered all three right, we did decide that he or she got a sound localization. This study defined improved sound localization as the case in which a test result was positive in aided condition regardless of an unaided result.