How is traffic noise measured?
Traffic-generated sound waves are described by two basic parameters: frequency and amplitude. Amplitude is the energy level or “loudness” of a sound wave and is measured in decibels (dB). Frequency refers to the number of sound waves produced within a given time period. Frequency is weighted according to an “A” scale to provide a more accurate representation of the ear’s sensitivity to sounds of various frequencies. The resulting sound levels are reported as dB(A). Sound is measured on a logarithmic scale.
