Sandwich panel : plywood / rubber (soundproofing)
World Panel

The basic insulation between two rooms is the difference in the levels of acoustic pressure measured in the transmitting room and in the receiving room. This includes all direct and indirect noises, and is expressed in dB (A).

The transmitted noise is known as ‘Rose’ (a constant level for all frequencies), and as ‘Route’ noise (taking account of the sensitivity of the ear to different frequencies)

The sound value of a wall allows evaluation of the direct transmission between one room and another.