Hearing Conservation, Occupational and Recreational Noise-Induced Hearing Loss
Custom Ear Protection
Advantages Custom made for better seal Filters of varying decibel reduction available Disadvantages Easier to loose and can become expensive Require good hygiene/cleaning
Ear Plugs
Advantages- Small and easily carried Convenient to use with other personal protection equipment (can be worn with ear muffs) More comfortable for long-term wear in hot, humid work areas Convenient for use in confined work areas Disadvantages-more difficult to insert and remove require good hygiene practices may irritate the ear canal Fingernail marks can decrease effectiveness more difficult to see and monitor use
Ear Muffs
Advantages- less attenuation variability among users designed so that one size fits most head sizes easily seen at a distance to assist in the monitoring of their use not easily misplaced or lost may be worn with minor ear infections Disadvantages- less portable and heavier more inconvenient for use with other personal protective equipment. more uncomfortable in hot, humid work area more inconvenient for use in confined work areas may interfere with the wearing of safety or prescription glasses: (gap creates a break in the seal and therefore can reduce effectiveness/attenuation
Consequences of NIHL
Communication difficulties Tinnitus Anxiety Lack in ability to concentrate Increased stress Depression Higher divorce rates Greater incidence of illness Loss of sleep Reduced productivity Increased blood pressure
Protect your hearing
Custom Ear Protection, Ear Plugs, and Ear Muffs
Headphones vs. Ear Buds
Ear buds (in the ear) - cause more damage when used the same amount of time as typical over-the-ear headphones (Ringen, 2005). Ear buds should be worn for no longer than 30 min./day. (Fligor, 2001) Headphones can be worn for 6 out of 10 hours a day. (Ringen, 2005)
Acoustic Trauma Notch
Hearing poorest in the 3000-6000 Hz frequency range with recovery at 8000 Hz. Damage to the basal turn of the cochlea related to that frequency range.
noise-induced hearing loss (NIHL)
Historically, men appear to have a higher incidence of hearing loss from noise than women more than 20 million Americans are exposed to hazardous sound levels on a regular basis. (American Academy of Audiology website) 1/3 of all the hearing impaired Americans have been affected at least, in part, by noise (American Academy of Audiology website) Two types of NIHL Occupational related noise-induced hearing loss Recreational noise-induced hearing loss Recreational activities have very few laws pertaining to safe sound levels and limits of excessive exposure. Lack of knowledge regarding the damage done. Noise-induced hearing loss is insidious, generally not noticed until permanent damage is done. It should be noted that the HL shown by a person exposed to noise can vary. The person's genetics, disease, aging and non-work related activities can effect their hearing as well.
Healthy People 2010
In 2000 the Department of Health and Human Services published Healthy People 2010 which called NIHL a "fully preventable condition". Recommended: Increased use of appropriate equipment and practices Reduce NIHL in children and adolescents aged 17 years and younger Reduce adult hearing loss in the noise-exposed public.
Noise- Induced Hearing Loss
Industrial Revolution- late 18th century Britain The steam engine! Temporary Threshold Shift (TTS) Permanent Threshold Shift (PTS)
Special Concerns for NIHL
Musicians rely more on the sense of hearing than many others who suffer from NIHL and may spend many hours a day exposed to intense sounds. Aerobic instructors and students may be at particular risk. Physical exercise plus noise results in greater threshold shifts than exposure to noise alone (Vittitow, Windmill, Yates & Cunningham, 1994) possibly due to effects on the cochlea of changes in metabolic activity during exercise. Air bags- sound pressure level of 150-170 decibels which lasts for 0.1 seconds
On the Rise
NIHL in adolescent population is on the rise...this is mainly due to the noise exposure seen especially with personal music devices Meyers- Bisch (1996) found: that individuals who used personal listening devices for greater than 2 hours/week experienced symptoms of auditory suffering and other hearing related problems. If used devices for more than 7 hours/week, increased the risk for NIHL Hearing loss in U.S. children aged 6-9 years: > 14% among boys and 10% in girls. (Niskar, Kieszak,Holmes, Esteban, Rubin, & Brady, 2001)
Noise Notch Audiogram
Noise induced hearing loss centers around the frequencies of 3000-6000 Hz. The hearing loss is sensorineural in nature. Can be a result of occupational or recreational exposure to loud sound
Occupational related noise-induced hearing loss
Noise-induced hearing loss as a result of a person's occupation or job
Recreational noise-induced hearing loss
Noise-induced hearing loss as a result of a person's recreational activities or hobbies
Occupational vs. Recreational Noise Exposure
Occupational- machinery, airplanes, printing press, power tools, gunfire, explosives, military and law enforcement Recreational- Music, Lawn equipment, Gunfire, Motorcycles
Decibel Levels
Painful 150 dB = fireworks at 3 feet 140 dB = firearms, jet engine 130 dB = jackhammer 120 dB = jet plane takeoff, siren Extremely Loud 110 dB = maximum output of some MP3 players, model airplane, chain saw 106 dB = gas lawn mower, snowblower 100 dB = hand drill, pneumatic drill 90 dB = subway, passing motorcycle Very Loud 80-90 dB = blow-dryer, kitchen blender, food processor 70 dB = busy traffic, vacuum cleaner, alarm clock Moderate 60 dB = typical conversation, dishwasher, clothes dryer 50 dB = moderate rainfall 40 dB = quiet room Faint 30 dB = whisper, quiet library
Permanent Threshold Shift (PTS)
Prolonged exposure to intense noise gradually damages the cochlear hair
OSHA
Recommended a scale: the time a worker may safely be exposed to intense sounds is decreased as the intensity of the noise is increased. Maximum exposure: 85dBA for 8 hr. day For every 3 dB increase in noise, half the time is allowed.
Prevention
Recreational hearing conservation programs are needed particularly for children and young adults to make them aware of the potential damage to their auditory systems. Practicing audiologists can screen individuals exposed to excessive noise annually using high frequency audiometry to detect any changes. Educate, educate, educate beginning with young children of the dangers of noise exposure. March 2006, Apple Computer announced a new tool that allows iPod users (or parents) to cap the volume and lock the setting with a password. (Apple.com) goPod- free downloadable computer program enables users to circumvent the controls to "release the sound of your iPod". (Apple.com)
Occupational Safety and Health Administration (OSHA)
The Hearing Conservation Amendment of 1983, requires hearing conservation programs in noisy work places. Yearly hearing tests required for the approximately five million workers exposed to an average of 85 dB or more of noise during an 8-hour work day.
Temporary Threshold Shift (TTS)
a reversible desensitization in hearing that disappears in anywhere from a few hours to several days
Acoustic Trauma
noise-induced hearing loss from impulsive sounds like explosions and gunfire. Usually a single incident, not from extended exposure to a loud sound