Indicators of subjective audiometry in the conventional frequency range in patients with COVID-19
Authors: Shidlovskaya Tetiana A. , Bezega Mychailo Iv. 
Published: December 2022

Sensorineural deafness (SND) is a polyetiological disease. The cause of perceptual hearing loss can be, among other things, viral infections. As a result of the pandemic of the SARS-CoV-2 virus, a significant number of patients with various clinical manifestations of the disease COVID-19 are observed, among which there are lesions of the central nervous, cardiovascular, and other systems. In addition, in the publications of researchers, there are reports of damage to the auditory analyzer. However, there is not enough information in the literature regarding the study of hearing function in patients with COVID-19.
The purpose of the study is to assess the state of auditory function according to subjective audiometry data in the conventional frequency range in pat ients with COVID-19.
Materials and methods: An analysis of subjective audiometry data in the conventional frequency range was conducted on 36 patients with COVID-19 who complained of hearing impairment after the disease. The examination was performed using audiometers AS-40 (Interacoustics, Denmark) and MA-31 (Germany).
Results and their discussion: To determine the indicators of subjective audiometry in patients with perceptual disorders of auditory function during COVID-19, we examined patients with complaints of decreased auditory function. Among 147 patients with COVID-19, during the survey, 51 people (34.7%) indicated certain disorders of the auditory system. During the instrumental examination of 47 patients with COVID-19 with complaints of hearing loss, we mainly observed sensorineural disorders of auditory function (36 people, 76.6%). Therefore, we analyzed subjective audiometry data in these patients.
In most cases, we observed a gently descending type of tonal audiometric curve with the greatest increase in hearing thresholds for tones in the high-frequency region of the conventional range.
The analysis of quantitative indicators of tone audiometry showed a significant increase in hearing thresholds for tones in the studied patients with COVID-19 compared to individuals of the control group. In patients with COVID-19, there is a significant (p<0.01) increase in hearing thresholds to tones, starting at 2 kHz, compared to controls. This increase was most pronounced at frequencies of 6 and 8 kHz, where the values were 31.2±1.5 and 34.5±1.9 dB, respectively.
Note that we did not find any significant differences in speech audiometry indicators in the studied patients compared to the indicators of the control group. However, some patients (7 people, 19.4%) complained of an inevitable deterioration in speech intelligibility. Moreover, three patients (8.3%) indicated that speech intelligibility impairment during communication occurred to them periodically.
Also, we did not detect any significant changes in the indicators of suprathreshold tests – Lüscher intensity differential threshold test and SiSi test in the studied patients. Although at the same time, some patients (8 people, 22.2%) complained about poor tolerance of loud sounds, which may indicate the presence of FPZH (the phenomenon of accelerated increase in loudness), and, therefore, the presence of receptor damage to the auditory analyzer.
Therefore, a third of patients (34.7%) may have a decrease in hearing function with the disease of COVID-19. Damage to the auditory system mainly (76.6% among all cases of hearing impairment) manifests as perceptual disturbances. Therefore, when examining patients suffering from COVID-19, we believe detecting disorders in the auditory system is advisable. Consequently, conducting an instrumental examination for those with hearing impairment complaints is advisable. On the other hand, when presenting patients with sensorineural deafness, it should be borne in mind that this may be related to a previous illness of COVID-19.
Conclusions:
1. With COVID-19, a third of patients (34.7%) experience auditory function impairment due to damage to the auditory system, mainly perceptual in nature – 76.6% among all hearing impairment cases.
2. Hearing disorders in the case of COVID-19 can be observed directly during the disease, but more often, such manifestations appear somewhat delayed from the onset or after a particular time after the disease.
3. The most pronounced significant (p<0.01) increase in hearing thresholds to tones in pat ients with COVID-19 with hearing impairment, compared to controls, occurs at frequencies of 6 and 8 kHz, where the values were 31.2±1.5 and 34.5±1.9 dB, respectively.
4. Patients with COVID-19 who have complaints of hearing impairment should undergo an instrumental audiological examination, first of all, subjective audiometry.