characteristic acoustic impedance

6.35  specific acoustic impedance, characteristic acoustic impedance. At a point in a medium, the complex ratio of sound pressure to particle velocity in the direction of the wave propagation. Unit, pascal per (meter per second) [Pa/(m/s)].

Annotation 1          In the MKS system of units, 1 rayl is equal to 1 pascal per (meter per second). An acoustic impedance of 1 rayl results from the application of 1 pascal of sound pressure producing a particle velocity of magnitude 1 meter per second.

Annotation 2          In the CGS system, 1 rayl is equal to 1(dyn · s) / cm³, which is equal to 10 rayls in the MKS system.