# Effect of Continuous Positive Airway Pressure Treatment on Hearing and Inner Ear Function in Patients with Obstructive Sleep Apnoea—Original Research

## TL;DR

This study found that CPAP therapy for sleep apnea does not improve hearing but improves cochlear function in patients who follow the treatment.

## Contribution

The study reveals that CPAP adherence improves cochlear receptor cell function at higher frequencies, despite no changes in hearing thresholds.

## Key findings

- CPAP therapy does not significantly change hearing thresholds in OSA patients.
- Cooperative CPAP users show improved cochlear receptor cell function at mid and high frequencies.
- Standard audiometry does not detect cochlear improvements from CPAP therapy.

## Abstract

Background and Objectives: This study aimed to investigate the influence of continuous positive airway pressure in patients with obstructive sleep apnoea on hearing and the possibility of recovering cochlear receptor cells. Materials and Methods: Forty-two patients with obstructive sleep apnoea (OSA) were assigned to the study group. Patients underwent pure-tone audiometry and transient-evoked (TEOAE) and distortion-product (DPOAE) otoacoustic emissions before starting continuous positive airway pressure (CPAP) therapy and six months after CPAP therapy. Subjects were further divided into the following two groups: those who adequately used the therapy and those who did not adhere to treatment recommendations. Results: There is no significant difference in hearing thresholds for specific frequencies after six months of CPAP therapy. There is no significant difference in TEOAE and DPOAE SNR values at any frequency after 6 months of CPAP therapy. There is no significant difference in hearing threshold results for specific frequencies as a function of subject co-operation with treatment. After therapy, there is a significant difference in the SNR values in TEOAEs at 2 kHz and 4 kHz in subjects of the OSA target group, depending on co-operation, being higher in co-operative subjects, while there are no significant differences at other frequencies. There is a significant difference in the SNR results in DPOAEs, where they are higher in co-operative subjects at 1000, 6000, 7000 and 8000 Hz. Conclusions: The use of continuous positive airway pressure as a therapy for OSA has no effect on hearing and cochlear receptor cell recovery. Co-operation with CPAP treatment does not affect hearing threshold, but does affect cochlear receptor cell function, which is better at mid and higher frequencies in those who co-operate. These findings underscore the clinical significance of treatment adherence. Consistent adherence is associated with measurable improvements in hearing, particularly at higher frequencies, which cannot typically be evaluated in routine clinical practice using standard pure-tone audiometry. Our results emphasise the importance of promoting compliance with CPAP therapy not only for cardiovascular and neurological protection, but also for maintaining hearing health.