Frequency and causes of hearing impairment in tertiary care center

Objective: To determine the frequency and causes of hearing impairment in patients attending the out patient department of Civil Hospital Karachi.Methods: This study was carried out at the ENT department of Civil Hospital Karachi from January 1998 to October 2000. Six hundred patients were randomly selected from the out patient department. Patients of all age groups and both genders were included, who complained of hearing impairment in one or both ears.Detailed history, complete E.N.T. examination and relevant audiological, radiological investigations were carried out.Results: Frequency of conductive hearing loss was 50%, sensorineural hearing loss 20% and mixed hearing loss in 30%. CSOM remains the most common cause in this study. In majority of cases of sensorineural hearing loss, prenatal and perinatal factors predominate. Consanguinity was the most frequent factor in this study in sensorineural type of hearing loss.Conclusion: Conductive hearing loss is more prevalent than sensorineural hearing loss by a ratio of 2.5:1. Otitis media remains the commonest cause in this study i.e. 76%. Prevention of prenatal and postnatal factors can decrease the frequency of sensorineural hearing loss.