When Mumps Silences an Ear: Audiovestibular Findings in Sudden Unilateral Hearing Loss – A Case Report

Abstract Mumps is an acute viral infection caused by a paramyxovirus, classically characterised by the swelling of the parotid gland and systemic symptoms (Hviid et al., 2008). Mumps is largely controlled through immunisation programs, but sporadic outbreaks continue to occur worldwide. Hearing loss is a rare but well-documented complication of mumps infection, with an incidence ranging from 0.005% to 0.3% (Hashimoto et al., 2009; Nomura & Harada, 1981). Hearing loss associated with mumps is typically sudden in onset, unilateral, severe to profound in degree, and often irreversible. Because of its rarity, early recognition may be delayed, which may result in long-term communicative and educational consequences in pediatric populations. Case presentation: An 11.2-year-old female presented with a complaint of sudden reduced hearing sensitivity in the right ear post-mumps infection (May 2025). A detailed audiological evaluation was carried out. Pure Tone Audiometry revealed severe to profound hearing loss in the right ear and normal hearing in the left ear. Speech identification scores could not be measured in the right ear, while in the left ear demonstrated a score of 100%. Immittance audiometry revealed an ‘A’ type tympanogram, which ruled out the presence of any middle ear pathology. Otoacoustic emissions were absent in the right ear, suggesting outer hair cell dysfunction, while they were present in the left ear. Auditory brainstem response revealed the absence of wave V at 90 dB nHL using both click and 500 Hz Tone Burst stimuli in the right ear, which supported cochlear pathology, while wave V was obtained till 30 dB nHL using the click stimulus in the left ear, which showed normal hearing. In addition, balance evaluation was also carried out by evaluating the Vestibular evoked myogenic potentials (VEMP) and the functional head impulse test, which revealed right-sided hypo-function of the vestibular system. The management option provided was a hearing aid, in which the aided responses were observed to be within the speech spectrum and a speech perception score of 72%. Conclusion This case highlights the importance of a comprehensive audiovestibular evaluation in the pediatric population presenting with sudden hearing loss after mumps infection. Early identification and timely rehabilitation are essential to minimise long-term communicative and developmental consequences.