However, psychologists distinguish between sound and noise. Sound is measured physically in decibels. 'Noise cannot be measured in the same way because it refers to the psychological effect of sound and its level of intensity depends on the situation. Thus. for passengers at an airport who expect to hear aeroplanes taking off and landing, there may be a lot of sound, but not much noise (that is, they are not bothered by the noise). By contrast, if you are at a concert and two people behind you are whispering, you feel they are talking noisily even if there is not much sound You notice the noise because it affects you psychologically