| Table 4 - Summation of Noise Levels | |
|---|---|
| Difference in dB(A) between two noise levels being summed | Amount in dB(A) to add to the higher noise level |
| 0 to 0.5 | 3.0 |
| 1.0 to 1.5 | 2.5 |
| 2.0 to 3.0 | 2.0 |
| 3.5 to 4.5 | 1.5 |
| 5.0 to 7.0 | 1.0 |
| 7.5 to 12.0 | 0.5 |
| more than 12.0 | 0 |
When using Table 4 noise levels should be summed in a pairwise fashion and the final total rounded to the nearest whole dB(A), with values of 0.5 or more being rounded upwards.
