A 10 dB difference in sound volume is subjectively perceived as the doubling or halving of the sound volume. Some indicative values: discussion: sound volume of about 50 dB, traffic noise 80 dB; heavy truck (at a distance of 5 m): 90 dB; sledge hammer (at a distance of 2 m): 100 dB. From an exposure of 65 dB (A) onwards, making telephone calls becomes difficult, and a value of less than 50 dB (A) is recommended for concentrated working.
