Since the sound perception of the human ear varies over the frequency range, the so-called A-weighting was introduced. With this, low and very high frequencies are only perceived at a higher sound pressure level compared to medium frequencies. The evaluation levels for the single third octave bands are made according to DIN EN ISO 3745. In the following table, these evaluation levels per third octave middle frequency are listed and shown graphically in figure 7.1.4. In addition to the A-weighting, the B- and C-weighting are further methods which are technically less relevant and are therefore not considered further.
| third octave band middle frequency in |
A-evaluation in |
|
| 1 | 50 | -30,2 |
| 2 | 63 | -26,2 |
| 3 | 80 | -22,5 |
| 4 | 100 | -19,1 |
| 5 | 125 | -16,1 |
| 6 | 160 | -13,4 |
| 7 | 200 | -10,9 |
| 8 | 250 | -8,6 |
| 9 | 315 | -6,6 |
| 10 | 400 | -4,8 |
| 11 | 500 | -3,2 |
| 12 | 630 | -1,9 |
| 13 | 800 | -0,8 |
| 14 | 1000 | 0,0 |
| 15 | 1250 | 0,6 |
| 16 | 1600 | 1,0 |
| 17 | 2000 | 1,2 |
| 18 | 2500 | 1,3 |
| 19 | 3150 | 1,2 |
| 20 | 4000 | 1,0 |
| 21 | 5000 | 0,5 |
| 22 | 6300 | -0,1 |
| 23 | 8000 | -1,1 |
| 24 | 10000 | -2,5 |
