| Level | Description |
| 100 dB (0.002 kPa) | Barely noticeable |
| 110 dB (0.006 kPa) | Readily acceptable. Rattling of loose windows/doors/ceiling panels |
| 128 dB (0.050 kPa) | Currently acceptable by South African authorities as being a reasonable level for public concern. No more than 10% of measurements should exceed this value) |
| 134 dB (0.100 kPa) | § Limit is 133dB if lower frequency limit of the instrument is 2Hz. § Currently accepted by South African authorities that damage will occur below this level. (No measurements should exceed this value outside of the mining boundaries.) -Good Highveld thunderstorm |
| 140 dB (0.200 kPa) | § Exceed by strong wind gusts § Poorly mounted pictures, rattling of objects on shelves/display units, potential for these to fall |
| 170 dB (6.3 kPa) | Will break a well mounted window |