Effect of noise emitted by forestry equipment on workers' hearing capacity

• We investigated the effect of noise on forest loggers hearing.
• The loggers were divided into four age groups and whether they used hearing protection.
• We measured their hearing threshold.
• We compared the loggers' hearing to that of normal population using OSHA age correction tables for audiograms.

Forest logging involves the use of various noise-producing equipment, which may be harmful to the hearing capabilities of operators in the immediate area. Yet, little research has been performed to determine the long term effect of noise on forest loggers. Therefore, the purpose of this study was to determine how noise from forestry work affects operators' hearing capabilities at different frequencies, in relation to their age, years of experience as forest loggers, and whether or not they regularly wore hearing protection equipment (HPE). Twenty-six male forest loggers who were directly involved with logging equipment operations participated in this study. They were divided into different groups depending on age (20–29, 30–39, 40–49, and 50–59), years of experience (1–10, 11–20, 21–30, and 31–40), and whether they used HPEs. A Beltone audiometer was used to measure hearing thresholds at different frequencies (125, 250, 500, 750, 1000, 2000, 4000, and 8000 Hz). To determine whether the loggers experienced threshold shifts, their hearing thresholds were compared with average persons’ hearing thresholds. The hearing threshold and threshold shift were found at 4000 Hz, and the lowest hearing thresholds were found at 500, 750, and 1000 Hz. According to results, as age increased, hearing threshold either increased or remained the same. This study also concluded that the years of experience or exposure to forestry equipment can adversely affect hearing. Participants that used HPE had lower hearing thresholds than participants that did not use HPE. By wearing HPE, forest workers may prevent hearing loss at 4000 Hz.Relevance to industryForest logging has adverse effect on the hearing of workers. Specifically the loggers who do not use hearing protection equipment are more susceptible to hearing loss. Therefore, the hearing of workers needs to be monitored on a regular basis and the use of HPE should be made mandatory.