Wideband Acoustic Immittance in Otitis Media With Various Levels of Effusion Analysis and Finite Element and Model Validation

LI Hang; LIU Peihan; JIANG Wen; LIU Houguang; QIAO Yuehua; LIU Wen

doi:10.3969/j.issn.1672-2922.2025.02.009

Abstract：Objective To determine the degree of middle ear effusion using wideband acoustic immittance and the relationship between middle ear pathology and acoustic absorptivity using a finite element method.Methods A total of 34 children diagnosed with otitis media with effusion(SOM)and 40 healthy children were recruited from January 2022 to July 2022,Department of Otolaryngology,Xuzhou Medical University Affiliated Hospital.Based the degrees of effusion,children with effusion were categorized as partial or full effusion.Characteristics of energy absorption between the two groups were compared.A finite element method was used to construct models of 25%,50%,64%and 100%fluid accumulation,and the rate of energy absorption was calculated.Results Children with SOM showed flat immitance curves lower than those in healthy children at 500-4000 Hz(P＜0.05).Sound absorption curves in children with full fluid accumulation were flat with no peaks,and lower than in those with partial fluid accumulation 800-6000 Hz(P＜0.05).The finite elements model showed a gradually decreases in rate of energy absorption with increase of fluid accumulation.With effusion at up to 25%of the middle ear cavity,the overall energy absorption curve paralleled that in normal human ears.The rate of energy absorption was about 20%when effusion reached 50%of middle ear volume at 800-8000 Hz,about 10%when fluid reached 64%of middle ear volume,and 0 when fluid reached 100%of middle ear volume.Conclusion The rate of wideband acoustic absorption varies with the level of tympanic effusion.The finite element model can simulate the state of middle ear effusion,showing sound energy absorption rates that can reflect the degree of tympanic effusion.