A study which has followed up on students who took part in a hearing conservation program in the early and mid 1990s in Wisconsin in the US among students, who worked or lived on farms, shows that many today have a hearing loss.
More people with hearing loss
Originally, the programme comprised of 690 participants. 16 years later, the researchers got in contact with 392 persons who were part of the original group. The 392 persons had their hearing checked with a hearing test.
63% of the persons now aged between 32–38 years old had a high frequency hearing loss of 10dB. 12% of the participants had a substantial hearing loss of 25dB or more. This is much higher than the normal levels seen in this age group.
Noise on farms
The reason why living and working on farms may result in a hearing loss is due to the noise from machines and animals. Noise is one of the most common causes of hearing loss. The sound of squealing pigs may reach as high as 130dB. Grain dryers and chain saws measure up to 110dB and a grain auger reaches 95dB. Maximum safe levels for humans are 85dB.
The study was carried out by the national Farm Medicine Center, a part of Marshfield Clinic Research Foundation.
The aim of the original programme was to intervene early to try to prevent hearing loss.