Occupational Noise Exposure in Hyperbaric Oxygen Therapy Centers: A Nationwide Study on the Sound Levels and Audiometric Impact on Operators in Türkiye

Abstract

Objective: This study aimed to measure noise levels in hyperbaric oxygen therapy (HBOT) centers across Türkiye and to evaluate their potential impact on the hearing thresholds of hyperbaric chamber operators. Material and Methods: Between November-December 2021, sound intensity measurements were conducted in 41 HBOT centers. Noise levels were recorded during the 4 operational phases using a calibrated sound level meter. Audiometric data from 28 eligible operators were retrospectively analyzed. Hearing thresholds were corrected for age and sex according to the European norm International Standart of Organization 7029:2017 standard to isolate occupational effects. Results: The maximum equivalent continuous sound level [Leq decibel (dB) (A)] was recorded as 81.9 dB(A), and the highest peak noise level [Lpeak dB(C)] was recorded as 114.5 dB(C). In 63.4% of the centers, the 70 dB(A) limit was exceeded during the treatment depth when the ventilation was on. A statistically significant hearing threshold shift at 4,000 Hz was observed in the right ear (p=0.039). No operator met the clinical criteria for noise-induced hearing loss (NIHL); however, the findings were suggestive of early cochlear involvement. Conclusion: Although no clinical NIHL was detected among the hyperbaric chamber operators, the significant threshold shift at 4,000 Hz, the frequency often first affected by noise exposure, indicates the early auditory effects of occupational noise exposure. In centers where noise levels exceed 70 dB(A), regular noise monitoring, routine audiometric evaluations, the use of hearing protection, and the implementation of engineering controls are recommended. These findings highlight the need for updated national regulations specifically tailored to HBOT centers. © 2025, Turkiye Klinikleri. All rights reserved.