Aetiology of Asymmetrical Hearing Loss: A Retro-spective Study Thesis Submitted for Partial Fulfillment of Master Degree in Audio-Vestibular Medicine

Hearing loss maybe: -Symmetrical: in which the severity and pattern of hearing loss are the same in each ear. Or -Asymmetrical: is defined as binaural difference in bone conduction thresholds of >10 dB at two consecutive frequencies or >20 dB at one frequency (0.25-8.0 kHz), Poorer speech perception will often accompany poorer hearing and may be the reason for the patient's presentation .Unilateral or asymmetrical sensorineural hearing loss is important to discern, as it is an important risk factor for auditory nerve tumors (i.e. vestibular schwannoma) which is a life threatening condition, and in such cases further investigation is required (i.e. MRI scan) unless there is a known reason for the asymmetry, Several reports have recommended that further evaluation, especially expensive imaging studies, be conducted to rule out acoustic tumors when AHL is present