TIEN-CHEN LIU2020-03-092020-03-0919991019-6102https://www.scopus.com/inward/record.uri?eid=2-s2.0-0033492145&partnerID=40&md5=ae0851fd7984729e84f329718f4d608ehttps://scholars.lib.ntu.edu.tw/handle/123456789/474538BACKGROUND: The purpose of this study is to investigate the relationship between functional gain and insertion gain in people with tympanic membrane perforation who use hearing aids. METHODS: Ten perforated ears served as the experimental group. The control group consisted of ten ears with comparable sensorineural hearing loss. Functional gain was obtained by subtracting the unaided threshold from the aided threshold in sound field audiometry. Insertion gain was measured using a Fonix 6500 probe-tube microphone system. RESULTS: In the control group, the average functional gains did not differ from the insertion gains across all frequencies. In the experimental group, the average insertion gains were significantly larger than functional gains in all frequencies. The differences between insertion gain and functional gain had a high positive correlation (r=0.86) with the average air-bone gap in the experimental group. CONCLUSIONS: Probe-tube microphone measurements of insertion gain substantially overestimate the functional gain of subjects with ear drum perforations. The difference is especially noticeable in patients with larger air-bone gaps. Therefore, the results of real ear measurements should be interpreted with caution.Functional gain; Hearing aid; Insertion gain; Tympanic membrane perforation[SDGs]SDG3adult; article; audiometry; auditory threshold; clinical article; eardrum perforation; functional assessment; hearing aid; human; microphone; perception deafnessjournal article2-s2.0-0033492145