Sound level (dB) | Approximate loudness relative to ordinary conversation | Perception example |
0 | Don’t hear anything | Threshold of hearing |
10 | 1/32 as loud | Very faint normal breathing |
20 | 1/16 as loud | Quiet room |
30 | 1/8 as loud | Quiet conversation/quiet office interior |
40 | 1/4 as loud | Moderate quiet office/quiet rural area |
50 | 1/2 as loud | Quiet suburban area/dishwasher in next room |
60 | Ordinary conversation | Average office/ordinary conversation |
70 | Twice as loud | Loud busy street/vacuum cleaner at 3 m |
80 | 4 times as loud | Noisy office/passing car at 3 m |
90 | 8 times as loud | Very loud heavy traffic/passing bus or truck at 3 m |
100 | 16 times as loud | Loud car horn/passing subway train at 3 m |
110 | 32 times as loud | Pop group/night club with band playing |
120 | 64 times as loud | Extreme; jet take-off at 100 m |