Determining the role of impacted cerumen in conductive hearing loss by simulation

Purpose: Hearing loss is the inability to perceive sound waves in the atmosphere due to pathology in the peripheral or central auditory pathways. Hearing losses are divided into three main groups: conductive, sensorineural and mixed. In conductive hearing loss, sound cannot be transmitted to the inner ear due to pathologies in the external ear or middle ear. In sensorineural hearing loss, the pathology is in the inner ear or more centrally. Approximately 15% of the adult population has hearing problems. The type of hearing loss varies according to age groups. As age increases, the prevalence of sensorineural hearing loss increases. Conductive hearing loss is most common in children at school and over the age of 70. Hearing loss due to cerumen in the external ear canal is the most common cause of conductive hearing loss. Cerumen is produced by the sebaceous glands in the cartilage portion of the external ear canal. It helps protect, clean and lubricate the outer ear canal. If the self-cleaning property of cerumen is impaired, cerumen accumulation is observed in the external ear canal. The aim of this thesis is to show the effect of cerumen accumulation on conductive hearing loss. Materials and Methods: We included 27 individuals who had no known ear-related disease and gave informed consent to the study. Firstly, bilateral pure tone audiometry was performed in this group. Then we used play dough to imitate the cerumen. We completely blocked the outer ear canal with play dough. Then, we drilled holes with diameters of 1.1 mm, 2.0 mm, 2.7 mm, and 3.3 mm in the center of the play dough, respectively, and repeated the hearing tests. Results: As the rate of obstruction of the external auditory canal by occlusive cerumen increases, the amount of hearing loss increases. We have shown that conductive hearing loss due to occlusive cerumen affects high frequencies more. For a significant hearing loss at low frequencies, the external auditory canal must be nearly total. Conclusion: Obstructive cerumen are the most common cause of conductive hearing loss. Obstructive cerumen can cause hearing loss regardless of size. This problem can be resolved with routine ear, nose and throat examination. Key words: Conductive hearing loss, Cerumen, Pure tone audiometry (PTA), External auditory canal occlusion