听力保护 Wear Your Hearing Protection.ppt

lt;p>&lt;p&gt;WEAR YOUR HEARING PROTECTION ! TWA8 – Time-weighted average 8-hour sound level (dBA) D – Noise Dose (%) – Action Level (TWA8 ≥ 85 dBA or D ≥ 50%) Operator must provide two plug types can cause a TTS as well Effects of Hearing Loss Hearing Protection Devices (HPD) Noise-induced hearing loss is preventable with the proper use of engineering safety glasses, hardhats Not very comfortable in hot weather – Perspiration can collect under the ear cup, causing annoying sounds in the ear canal Proper Use of Hearing Protection Proper fit should be determined by an occupational hearing conservationist (OHC) Earmuffs don’t fit all head sizes Proper Use of Hearing Protection Earplugs must be properly inserted source: http://www.cdc.gov/niosh/mining/topics/hearingloss/earplug.htm – 1. Roll the earplug up into a small, thin &amp;quot;snake&amp;quot; with your fingers. You can use one or both hands. – 2. Pull the top of your ear up and back with your opposite hand to straighten out your ear canal. The rolled-up earplug should slide right in. – 3. Hold the earplug in with your finger. Count to 20 or 30 out loud while waiting for the plug to expand and fill the ear canal. Your voice will sound muffled when the plug has made a good seal. – Check the fit when youre all done. Most of the foam body of the earplug should be within the ear canal. Try cupping your hands tightly over your ears. If sounds are much more muffled with your hands in place, the earplug may not be sealing properly. Take the earplug out and try again.Illustrations and Photo courtesy of NIOSH Maintenance of Hearing Protection Devices Hygiene – Pre-molded earplugs should be washed – Disposable plugs should be discarded after each shift or if they become dirty – Earmuff cushions should be wiped off regularly – Hearing protection should not be used when you have an ear infection Replacement – Pre-molded plugs shrink and harden over time and should be replaced if this occurs – Earplugs should return to their original shape otherwise they should be discarded – Earmuffs should be checked to ensure a good seal is formed against the head Headbands weaken with age or sometimes become sprung Cushions eventually harden and fail Ear cups can become brittle and crack with age Performance of Hearing Protection Noise reduction rating (NRR) – Standardized measure of noise reduction provided by a hearing protector as measured in the laboratory – Not used to predict what the user will or will not hear i.e., it’s a relative measure similar to EPA gas mileage – Provides for a comparison when choosing a suitable protector for the intended use “Dual protection” – use of earplugs and earmuffs required when levels exceed 105 dBA – Do not add NRR values for double protection Typically add 5 dB to the NRR of the more protective device Wear Your Hearing Protection Hearing loss due to improper use of hearing protection often goes unnoticed – There are no visible effects, no bleeding, and often no pain – There is only a gradual, progressive loss of communication with family and friends, and a loss of sensitivity to the environment Noise-induced hearing loss is preventable – Proper use and selection of hearing protection is a must – Hearing protection in combination with noise controls is the best method of prevention PROPERPROPER IMPROPERIMPROPER Wear Your Hearing Protection – Miners’ hearing is precious and we need to work together to preserve their quality of life &lt;/p&gt;</p>。