Noise Exposure and its Effects on the Hearing of Indoor Cycling Instructors

To ascertain the influence of occupational exposure to SPL on the hearing threshold of indoor cycling (IC) instructors. This is a cross-sectional study involving eleven IC instructors at fitness centers in Guarapuava, PR, Brazil Questionnaires were applied to assess occupational characteristics and reported auditory and extra-auditory symptoms. The hearing threshold was evaluated by pure tone audiometry testing at seven moments: after 14 h of acoustic rest, and before and immediately after exposure to SPLs of 95, 85 and 75 dB(A), making a total of 77 measurements of the group of instructors. Differences in means were assessed using the Kruskal–Wallis test. The k-means and composition method was applied using principal component analysis to verify the main factors associated with the broadband multi-frequency measurement at the hearing threshold. The average bilateral hearing threshold showed a significant increase at the intensity of 95 dB(A), at all the tested frequencies (p < 0.05) and at most of the frequencies, at 85 dB(A). Conclusions exposure to the equivalent sound pressure levels of 85 dB(A) and 95 dB(A) significantly altered the average hearing threshold of indoor cycling instructors.