Talking with

a normal voice approximates to a sound pressure level of 70 dB

a raised voice approximates to a sound pressure level of 76 dB

a very loud voice approximates to a sound pressure level of 82 dB

a shouting voice approximates to a sound pressure level of 88 dB

at a distance of 1 ft (0.3 m).

For every doubling of the distance from the noise source the sound pressure level decrease with 6 decibels:

Distance Voice Level (dB) (ft) (m) Normal Raised Very Loud Shouting 1 0.3 70 76 82 88 3 0.9 60 66 72 78 6 1.8 54 60 66 72 12 3.7 48 54 60 66 24 7.3 42 48 54 60

In social settings people often talk with normal voice levels at distances ranging 1 to 4 metre. In such cases background noise levels should not exceed 55 to 60 dB(A).

In outdoor play and recreational areas people often communicate with raised or very loud voices at distances 5 to 10 metre and the background noise should not exceed 45 to 55 dB(A).