Passenger Compartment Acoustic Absorption
The noise within a passenger compartment is controlled by a number of parameters, one of those is the acoustic absorption within the compartment.
One method of establishing the amount of acoustic absorption within the compartment is to measure the reverberation time. The faster sound decays in the volume the more absorption that is present.
Measuring the reverberation time in conjunction with the sound pressure level in the compartment during normal operation will allow the acoustic power of the noise to be infered along with the acoustic attenuation. Knowing these two parameters will allow any noise reduction techniques to be optimised.