Background Category | |||||||
Octave-Band Center Frequency (Hz) | 1 | 2 | 3 | 4 | 5 | ||
31 | 60 | 55 | 50 | 44 | 38 | ||
63 | 61 | 56 | 52 | 46 | 40 | ||
125 | 62 | 56 | 52 | 46 | 40 | ||
250 | 60 | 55 | 50 | 44 | 38 | ||
500 | 57 | 51 | 46 | 40 | 34 | ||
1000 | 53 | 46 | 40 | 34 | 28 | ||
2000 | 47 | 40 | 33 | 28 | 21 | ||
4000 | 43 | 34 | 25 | 20 | 15 | ||
8000 | 38 | 28 | 19 | 14 | 8 |
Ill. Admin. Code tit. 35, pt. 910, app A, tbl. D