What is the maximum permissible noise exposure level at 97 dB, as specified?

The maximum permissible noise exposure level of 97 dB is associated with a specific limit on the duration of exposure to protect hearing. Generally, as noise levels increase, the permissible exposure time decreases.

At 97 dB, the recommended exposure limit is typically around 3 hours. This is based on guidelines from organizations such as the Occupational Safety and Health Administration (OSHA) and the National Institute for Occupational Safety and Health (NIOSH), which suggest that continuous exposure at this sound level increases the risk of hearing damage.

In practical terms, sound at this level is quite loud, comparable to heavy traffic or a subway train, hence the need to limit exposure time to minimize the risk of noise-induced hearing loss. Therefore, 3 hours is considered the safe maximum exposure time for 97 dB, ensuring optimal hearing protection in environments where such noise levels are common.