Hearing quiz

When the noise level on a jobsite reaches 85 decibels over an 8-hour time weighted average, hearing
protection must be provided. Earplugs come in a variety of types and sizes. Foam earplugs are the most
common. Earmuffs are also used by construction workers. Sometimes, double ear protection is required
and then the worker must wear earplugs and muffs. Earplugs and ear-muffs must be worn properly to be
sure their Noise Reduction Rating is actually achieved. Noise Reduction Rating (NRR) is the number of
decibels the equipment will subtract from what the person actually hears. Workers must be trained to use
the equipment they have been issued. To insert earplugs, one should reach over his/her head to pull open
the ear canal, twist between two fingers, and insert it in the ear. It will then expand to fill the canal
opening. If the company participates in a hearing conservation program, then audiometric testing must be
included for each affected employee. A baseline test and then annual tests must be offered. The annual
test is compared to the baseline. Signs are posted when hearing protection is required. The first
frequencies to show damage from noise are those between 3000 and 6000 Hz, the same as human
speech. Hearing damage from noise is usually permanent. Activities such as jack-hammering, pile-
sheetdriving, rivet-busting, use of powered tools and machinery and operation of powder actuated tools
are examples of activities that produce noise from which employees must be protected.