ABSTRACT
Objective: To get insight into the current practice of noise reduction effect of workers as they wore hearing protectors in different domestic enterprises and the possible affected factors. Methods: From October 2020 to April 2021, using a random sampling method, 1197 workers exposed to noise in petrochemical factories, textile factories, and parts manufacturing factories were selected as the study subjects. The noise reduction effect of hearing protectors worn by workers in daily use was tested using a hearing protector suitability testing system. The personal sound attenuation level (PAR) was compared among workers in three enterprises, Targeted intervention and repetitive testing were conducted for workers who did not meet the noise reduction effect required by the enterprise, and the changes in PAR of workers before and after the intervention were compared. The comparison of baseline PARs between two or more groups was performed using the Mann Whitney test, the comparison of baseline PARs with post intervention PARs was performed using the Wilcoxon signed rank sum test, and the comparison of qualitative data between two or more groups was performed using the Chi square test. Results: The median baseline PAR for all workers was 15 dB. Men, age<30 years old, education level at or above college level, working experience of 5 to 15 years, and those who used hearing protectors for 5 to 15 years had higher PARs, with statistically significant differences (P<0.05). The median difference in baseline PAR among workers from three enterprises was statistically significant (H=175.06, P<0.01). The median PAR of subjects who did not pass the baseline increased from 3 dB to 21 dB after intervention (Z=-27.92, P<0.01) . Conclusion: Some workers wearing hearing protectors do not meet the required PAR, and low PARs may be related to incorrect wearing methods and incorrect selection of hearing protectors. As a tool for testing, training, and assisting in selection, the hearing protector suitability testing system is of great significance for worker hearing protection.
Subject(s)
Male , Humans , Adult , Hearing Loss, Noise-Induced/prevention & control , Ear Protective Devices , Noise, Occupational/prevention & control , Hearing , AudiometryABSTRACT
Contexto: los efectos de la exposición a la contaminación sonora incluyen síntomas auditivos como hipoacusia, elevación del umbral auditivo, trauma acústico y también no auditivos de tipo psicológico, físico y social. Material y métodos: estudio descriptivo analítico y transversal para determinar la eficacia de la atenuación sonora de los protectores auditivos personalizados en un grupo de 33 pacientes hombres sin alteraciones físicas del conducto auditivo externo, mediante la comparación de las respuestas obtenidas en el oído real libre y sin amplificación (Real-Ear Unaided Response) y con el oído herméticamente ocluido por medio de un tapón de silicona hecho a la medida (Real-Ear Occluded), ante la presencia de un ruido externo estable de banda ancha de 65 dB de intensidad, utilizando para ello un equipo de precisión certificado con normas ISO (Verifit de Audioscan). Resultados: se encontró que existe mayor protección a los decibeles altos con las frecuencias: 2000 Hz, 3000 Hz y 4000 Hz, bajando de 65 a 40 decibeles que traduce una reducción del 61%; no existe diferencia significativa entre ambos oídos, lo cual se explica por las particularidades en las formas anatómicas, profundidad de la inserción y la adecuada colocación de la sonda microfónica. Los valores promedio de atenuación bilateral en dB SPL que se logra en las diferentes frecuencias con tapones personalizados de protección auditiva varían dependiendo de la misma, con 250 Hz es de 9,97 en el oído derecho y 9,36 en el oído izquierdo y con 6000 Hz 15,28 en el oído derecho y 13,64 en el oído izquierdo. Una mayor atenuación se encontró con 3000 Hz (OD: 32,11 OI: 30,69), 2000 Hz (OD: 28,33 OI: 28,47) y 4000 Hz (OD: 27,28 OI: 26,67). Conclusión: el uso de protectores auditivo logra una evidente reducción de los niveles sonoros, sobre todo con frecuencias agudas (primeras) cuyos umbrales se afectan al someterse a elevados niveles de ruido por tiempos prolongados. (AU)
Context: the effects of exposure to noise pollution include auditory symptoms: hearing loss, elevation of the auditory threshold, acoustic trauma and also non-auditory psychological, physical and social. Material and methods: a descriptive, analytical, cross-sectional study, the efficacy of the sound attenuation of the personalized hearing protectors was determined in a group of 33 male patients without physical alterations in the external auditory canal, by means of the comparison of the responses obtained in the ear Real-Ear Unaided Response, and with the ear sealed by means of a custom-made silicone plug (Real-Ear Occluded), in the presence of stable external broadband noise of 65 dB Of intensity, using a precision equipment certified with ISO standards, the Verifit of Audioscan. Results: it was found that there is a greater protection to high decibels with frequencies 2000 Hz, 3000 Hz and 4000 Hz, falling from 65 to 40 decibels, which means a reduction of 61%, there is no significant difference between both ears, Which is explained by the particularities in the anatomical forms, depth of insertion and the proper placement of the microphone probe. The average bilateral attenuation values in dB SPL that is achieved in the different frequencies with personalized ear protection plugs vary depending on the same, with 250 Hz being 9.97 in the right ear and 9.36 in the left ear and with 6000 Hz 15.28 in the right ear and 13.64 in the left ear. Greater attenuation was found with 3000 Hz (OD: 32.11 OI: 30.69), 2000 Hz (OD: 28.33 OI: 28.47) and 4000 Hz (OD: 27.28 OI: 26.67). Conclusion: the use of hearing protectors; Achieves an evident reduction of the sound levels, especially with acute frequencies, which are the first ones whose thresholds are affected when undergoing high levels of noise for prolonged times. Keywords: sound attenuation, hearing protectors, noise induced hearing loss, auditory contamination