This is a confusing area. Scientifically sound intensity is defined as the sound power per unit area and is measured in watts/m2 . However the words ‘sound intensity level’ are often used instead and this relates to the measured ‘sound intensity’ (watts/m2) compared to the measured intensity to the threshold of hearing (which is 10-12 watts/m2). This ratio gives a value which is given units of decibels. Even more confusing in everyday practice ‘sound intensity’ is measured as a sound pressure level: the ratio of the measured sound pressure level (in Pascals) relative to the measured sound pressure level of the threshold of hearing (which is 2X10-5 Pascals) is also given units of decibels! There is a link as sound power is proportional to sound pressure squared.
Sound intensity RS_admin