Sound level reference values
Jackhammer
Airbus A320
Cars in front of the terminal
The very faint noise in a range between 0 and 20 dB can in fact only be measured in sound-proofed labs, because ordinary ambient noise will always exceed these levels. Even that »absolute silence« in the remotest place outside shows noise levels of between 20 and 30 dB. A standard A filter is used in order to take into consideration the varying sensitivity for very high and deep sounds among individual persons. The unit of measurement is thus referred to as dB(A).
The following »rule of thumb« is used to express the relation between measured sound pressure level and distance to the source of noise: Tripling the distance reduces the sound pressure level by 10 dB and thus halves the perceived noise exposure.
| Type of noise | Sound pressure level |
|---|---|
| Hearing threshold | 0 dB (A) |
| Breathing noise at a distance of about 1 m | 25 dB (A) |
| Very quiet room | 20-30 dB (A) |
| Ticking alarm clock | 30-35 dB (A) |
| Rustling leaves | 30-40 dB (A) |
| Whispering | 40 dB (A) |
| Conversation at a distance of about 1 m | 50-60 dB (A) |
| Aircraft DA 20 Katana (2-seater, 0.7 t MTOW), passing at an elevation of 300 m | 60 dB (A) |
| TV at »room volume« at a distance of about 1 m | 55-60 dB (A) |
| Shouting | 70 dB (A) |
| Car at a distance of about 10 m | 60-80 dB (A) |
| Aircraft ATR 42 (up to 50 seats, 16 t MTOW) during take-off, at a distance of about 300 m | 75 dB (A) |
| Aircraft AVRO RJ (up to 112 seats, 44 t MTOW) during take-off, at a distance of about 300 m | 80 dB (A) |
| Main road at a distance of about 10 m | 80-85 dB (A) |
| Aircraft Airbus A320 (up to 180 seats, 74 t MTOW) during take-off, at a distance of about 300 m | 85 dB (A) |
| Jackhammer at a distance of 1 m, heavy truck at a distance of 5 m | 90 dB (A) |
| Aircraft Boeing 747-400 (up to 524 seats, 386 t MTOW) during take-off, at a distance of about 300 m | 90 dB (A) |
| Night club | 110-120 dB (A) |
| Car horn at a distance of a few metres | 110 dB (A) |
| Threshold of pain | about 130 dB (A) |
MTOW = Maximum Take-Off-Weight