sound immission The introduction in the environment of noise deriving from various sources that can be grouped in: transportation activities, industrial activities and daily normal activities
sound measurement Because of the large variations in sound magnitudes, and because the human hearing sensation seems to vary in a logarithmic way, logarithms are used in measurement of sound. The sound pressure level is given in decibels (dB)
sound propagation The travelling of acoustic waves in the atmosphere with a speed independent of their amplitude. The speed only depends on the acoustic medium and is proportional to the square route of the absolute temperature for any given medium