Question

noise in the workplace is very common. it can lead to loss of hearing, if adequate precautions are not taken.
the noise level or volume can be measured in decibels: db(a).
some examples:

• normal conversation: 60 db(a)
• electrical appliances: > 85 db(a)
• power drill: 100 db(a)

it is advisable to use ear protection at noise levels greater than 80 db(a).
common types of ear protection:

• ear muffs

are worn over the ears.

• custom - molded ear plugs

individually made - to - measure ear protection.

• ear plugs

the ear plug is kneaded and then put in the ear. on expansion, the hearing channel is closed off, resulting in noise reduction.
note: dont ever use combinations of ear protection. the noise via bone conduction can damage hearing.
above which noise level or db(a) is ear protection advisable?

Explanation:

Step1: Identify key - statement

The text states "It is advisable to use ear protection at noise levels greater than 80 dB(A)."

Answer:

80