The influence of the environment on the sound power output of a source of low impedance

Whereas it has been known for years that the radiated sound power of a source of high acoustic impedance with appropriate spatial averaging equals the free field sound power in a reverberation room, the influence of the room on the sound power output of a source of low acoustic impedance has not received a similar attention. On the basis of theoretical considerations some authors have maintained that the sound power output of such sources would be reduced in reverberant surroundings, but this has never been verified. However, this is a matter of some concern, since standardised reference sources are aerodynamic sources of low acoustic impedance.
A theoretical and experimental investigation of the matter has been carried out. No systematic influence has been found.
Most of the computer simulations and all the experiments were carried out by Lars Mikael Verholt as a part of his MSc thesis work.