Table 2. Maximum Permissible Ambient Noise Levels (MPANL; dB SPL) in ANSI S3.1–1999 for Ears not Covered.

Ears not covered
Center frequency	MPANL
125	24.0
250	16.0
500	11.0
800	10.0
1,000	8.0
1,600	9.0
2,000	9.0
3,150	8.0
4,000	6.0
6,300	8.0
8,000	9.0