Hearing protectors of the cover type and cover attached to a helmet and their attenuation in women and men

Abstract

Currently, workers who are exposed to noise are at risk of progressive hearing loss. The main preventive measure is the use of hearing protectors (HP), which attenuate noise and may vary depending on different causes of leakage. The objective was to analyze the attenuation of earmuffs (EM) and earmuffs attached to a helmet (EMH) and their attenuation according to gender.

The study was descriptive, correlational, and cross-sectional. Examiners from the Centro de Investigación y Transferencia en Acústica (CINTRA) Universidad Tecnológica Nacional (UTN) - CONICET, measured hearing thresholds with and without HP at frequencies from 125 to 8000 Hz, following the recommendations of the Argentine Institute of Standardization and Certification standard 4060-1/1999 (IRAM). Participants aged 18 to 50 years provided informed consent and were assessed during the year 2019 and early 2020. They also had prior auditory rest and  hearing thresholds ≤ 15 dB at frequencies from 250 to 2000 Hz and ≤ 25 dB at 4000 and 8000 Hz. HP with minimum attenuation values required by IRAM were included. The presence of fatigue, flu-like symptoms, ear canal obstructions, or malformations was excluded.

The sample consisted of secondary data, comprising 304 EM: 116 females and 188 males, and 240 EMH: 79 females and 161 males. Descriptive analysis was performed, and the T-test and Wilcoxon test were applied, considering a significance level of 5%. In the sample, the average attenuation by frequency ranged from 16.08 dB to 39.41 dB in EM and from 14.14 dB to 35.37 dB in EMH, with statistically significant differences in most frequencies except 4000 Hz. Regarding gender, the attenuation of both protectors was similar, with greater attenuation at frequencies of 4000 and 8000 Hz in females and 125 to 2000 Hz in males.

In conclusion, EM showed higher attenuation values compared to EMH. In both protectors, attenuation values in low to mid frequencies are higher in males, and in high frequencies, they are higher in females.