DISCREPANCY IN SOUND POWER DETERMINATION AT LOW FREQUENCIES

摘要

The determination of the sound power of a source is simple in a reverberation chamber,but usuallylower valves are obtained at low frequencies than the free-space value.It is shown that the sound powerdetermined in a reverberation chamber depends not only on its free-space power,but also on the positions of the source and the reveiver,as well as the way the measurements are made and averaged.Exactand statistical formulas are derived to account for these factors.The results explain the discrepancy andagree well with earlier experiments.Based on the theory,parcticable techniques of sound power determina-tion are propesed and correct power formulas presented.