Which statement correctly describes the exposure criteria for Impact/Impulse Noise?

• A. Above 140 dB requires hearing protection only
• B. Above 120 dB requires enrollment in HCP
• C. 8-hr TWA above 85 triggers HCP
• D. Above 140 dB requires hearing protection and enrollment in HCP

Answer: (D)

Impact/impulse noise is evaluated by peak sound pressure levels, not by the 8-hour average. When a single or brief noise event exceeds 140 dB peak SPL, the required response is to provide hearing protection and enroll the worker in the Hearing Conservation Program. The PPE protects the ear from the high-energy spike, while enrollment in the HCP ensures medical surveillance, baseline and periodic audiograms, training, and ongoing program management to monitor and reduce hearing loss risk.

The other options don’t fit because they rely on either the wrong metric (8-hour TWA for impulse noise) or the wrong threshold (120 dB) or suggest PPE alone. The correct approach combines both protection and program enrollment for peak exposures above 140 dB.