Abstract
Background: Hypothyroidism, deficiency of thyroid hormone, is associated with many symptom complexes, one of them being hearing loss. Hearing loss in hypothyroidism may be the result of decreased cellular energy production, which compromises the microcirculation and thereby the metabolism and oxygenation of the middle ear and inner ear structures.

Aims and Objectives: In this study, we evaluated the hearing loss in hypothyroid patients of age group of 18–45 years and compared them with that in healthy people. Furthermore, we compared the severity of hearing loss with the extent of thyroid hormone deficiency in the hypothyroid group.

Materials and Methods: A case–control study was conducted in subjects aged between 18 and 45 years, in which 80 hypothyroid cases were selected after proper exclusion and informed consent and 80 age- and sex-matched healthy controls were studied. Hearing loss was assessed by pure tone audiometry, impedance audiometry, and distortion product otoacoustic emission tests. Statistical Package for the Social Sciences version 18 was used for statistical analysis.

Results: About 66.3% of hypothyroid adults had mild hearing loss affecting the higher frequencies which were characteristically bilateral and mostly sensorineural. A decrease in thyroid hormones was closely related to the severity of hearing loss.

Conclusion: Hypothyroid patients were more prone to sensorineural hearing loss. In patients with thyroid disorders, hearing evaluation helps in the detection of hearing loss earlier, and thus, treatment could be started.

Key words: Adult Hypothyroidism; Hearing; Audiometry; Tympanometry; Otoacoustic Emission; Tympanic Reflex