Subjective audiometry data in individuals who have recovered from COVID-19

Abstract

The purpose of this study is to investigate subjective audiometry parameters in individuals who have recovered from COVID-19. Materials and methods. Fifty-four patients who had recovered from COVID-19 and reported hearing-related complaints were examined. Audiometric testing was conducted in a soundproof booth, using a clinical AC-40 audiometer (Interacoustics, Denmark). Results and discussion. Patients who had recovered from COVID-19 reported auditory complaints, including hearing loss, impaired speech discrimination, subjective tinnitus, and a sensation of ear fullness. Pure-tone audiometry revealed sensorineural hearing loss with a descending audiometric curve. The mean hearing thresholds for pure tones in post-COVID-19 patients were significantly (P < 0,05) elevated compared to controls in the conventional frequency range, starting from 1 kHz. The most pronounced increase was observed in the 4–8 kHz range: the thresholds were 28,29 ± 5,61 dB at 4 kHz, 35,45 ± 3,62 dB at 6 kHz, and 41,45 ± 3,93 dB at 8 kHz. The thresholds for extended high-frequency tones were as follows: 9 kHz – 56,78 ± 3,39 dB; 10 kHz – 45,22 ± 4,35 dB; 11 kHz – 50,68 ± 5,89 dB; 12 kHz – 66,95 ± 7,75 dB; 14 kHz – 68,72 ± 6,46 dB; 16 kHz – 70,18 ± 5,59 dB. The mean speech discrimination thresholds tests were slightly elevated in the post-COVID-19 patient group, however, were not statistically significant. Differential thresholds measured using the Lüscher’s method were within the normal range at 0,5 and 1 kHz, at 4 kHz, were slightly reduced (0,78 ± 0,12 dB), which may indicate receptor-level dysfunction of the auditory system in post-COVID-19 patients. Conclusions: 1. According to subjective audiometry data, patients with COVID-19 exhibited sensorineural hearing impairments characterized by a gently descending form of pure-tone audiometric curves. 2. The most significant and statistically reliable (P < 0,01) elevation of hearing thresholds in post-COVID-19 individuals was observed for tones in the high-frequency range 4–8 and 10–16 kHz. 3. The results of subjective audiometry indicate the importance of assessing auditory function in patients with COVID-19, particularly using high-frequency audiometry, which enables timely detection of auditory analyzer impairment in such patients.