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