The Frequency Attenuations of Foam Ear Plugs Affected by User Error of College Students

This paper examines the relationship between the attenuating ability of foam ear plugs at low and high frequencies and the effects of incorrect ear plug fitting by college students. The National Institute for Occupational Safety and Health (1998) recommends the use of a hearing protection device (HPD) such as ear muffs or ear plugs to avoid noise induced hearing loss (NIHL). However, when not inserted properly, a HPD\u27s effectiveness can be adversely affected by user error and present as a decrease in attenuation. Attenuation is measured and presented on packaging as the noise reduction rating (NRR). A high NRR affected by user error can create a false sense of security, resulting in the frequent misuse of hearing protection. This paper explores the effect of user error in college students on foam ear plug attenuation by determining whether low or high frequencies are most perceived by the participant in audiometric testing. Testing utilized narrow band noise (NBN) and warble tones as stimuli presented in a sound field. Participants were asked to listen for the presented stimulus while wearing foam ear plugs fit by themselves as well as ear plugs fit by a trained experimenter. Results showed user error was greater in the lower frequencies than the higher frequencies. Additionally, there was no clinically significant difference between NBN trials and warble tone trials. Keywords: user error, hearing protection devices, noise reduction ratin