Precise selection of bone conduction hearing devices for congenital malformation of the middle and outer ear (CMMOE)

Abstract

Background: No selection criteria for the four bone conduction hearing devices yet. Aims/Objectives: To compare effectiveness of four bone conduction hearing devices in patients with bilateral Congenital Malformation of the Middle and Outer Ear (CMMOE). Material and Methods: 24 Patients (25 ears) were divided into five groups: 1) Bone Anchored Hearing Aid softband (BAHA-s), 2) BAHA implant (BAHA-i nested within group 1), 3) Vibration Sound Bridge implant (VSB-i), 4) Bone Bridge implant (BB-i), and 5) Bone Conduction Hearing Aid softband (BCHA-s). One patient implanted VSB and BB. Auditory parameters were compared: 1. Communication, 2. Average Air Conduction Thresholds (ACT) of pure tone, 3. Sentence Recognition Scores in quiet (SRS-q) and noisy (SRS-n) settings. The one-way analysis of variance (ANOVA) were employed to compare the differences in ACT and SRS-q/n among the groups, a statistical significance level of P < 0.05 was applied. Results: After hearing aid usage, all 24 patients (25 ears) reached or approached the normal in communication (i.e. from difficult to smooth), average ACT and SRS-q/SRS-n (no difference among groups, p > 0 .05). However, there was the difference in the optimal frequency of ACT and the absolute value of SRS-q/SRS-n for VSB/BAHA implants was higher than that for BB and BAHA softband. Conclusions and Significance: The precise selection of the four hearing devices mainly depends on patient’s hearing level, the optimal frequency of ACT and absolute values of SRS-q/SRS-n.