Double protection threshold: Extended > 104 dB for 8 hours.

• A. Extended > 84 dB for 8 hours
• B. Extended > 110 dB for 4 hours
• C. Extended > 104 dB for 8 hours
• D. Peak 150 dB

Answer: (C)

In hearing protection planning, there are specific limits for how long you can be exposed to a given noise level when using protective equipment. For extended protection, the defined limit is 104 dB for eight hours. That means if the environment is at or below 104 dB, you can be exposed for up to eight hours with double protection; higher levels require shorter exposure or additional protection. The other options don’t match this eight-hour extended threshold: one suggests a lower limit (84 dB) for eight hours, another gives a higher level (110 dB) but for only four hours, and the last refers to a peak level (150 dB) which is an instantaneous event, not an eight-hour exposure. The statement that matches the standard extended threshold is the one that says extended exposure above 104 dB is allowable for eight hours, which is why it’s the correct choice.