BONE CONDUCTION THRESHOLD VALUES RELATED TO OCCLUSION EFFECT AND CORRELATION WITH TYMPANOMETRIC VALUES
1İstanbul Aydın üniversitesi, Sağlık Bilimleri Enstitüsü, Odyoloji, İstanbul, Türkiye2İstanbul Medipol Üniversitesi, Odyoloji, İstanbul, Türkiye Introduction: The role of occlusion in the masking of bone conduction thresholds is great and is used to determine the mask baseline level. The aim of this study is to examine the changes of the occlusion effect and to investigate the factors causing this change.
Material - Method: The participants of the study consisted of 12 women and 12 men aged 17-25 with hearing thresholds within normal limits, having normal otoscopic examination and normal tympanogram. Tests at different frequencies (250-4000 Hz) are applied; The changes of the occlusion effect with the supraaural earphone (SAK), superficial and deeply placed foam plug, and the pressure effect applied to the ear at + 300 daPa were examined. In all measurements, Interacoustic AC40 hybrid audiometer, TDH-39 supraaural earphone, Insert Earphone (IE) ER3-14A, Radioear B-71 BC oscillator as bone vibrators and Titan ABRIS acoustic admittance meter were used.
Results: It was found that the size of the OE was dependent on the volume of compressed air between the plug used and the tympanic membrane. (p <0.05) In our study, it was found that when the tympanic membrane movement was restricted at +300 daPa pressure, occlusion effect did not occur and osseotimpanic bone conduction theory was effective in occlusion. (p> 0.05) The effects of osseotimpanic bone conduction theory on occlusion, one of the bone conduction theories. it was considered worth the research.
Conclusion: In the study, pressure was applied to the ear canal (+300 daPa) and no occlusion effect value was found. Depending on the restriction in the movement of the tympanic membrane, there may be a negative decrease in the thresholds in accordance with the ossetympanic theory. Accordingly, it is possible to develop insert headphones that can apply pressure from the external ear canal to the patients to solve the masking dilemma.
Keywords : Bone Conduction Threshold Evaluation; Masking; Occlusion Effect