Question

For testing, a reference sound source is used in an equipment room. The sound source that has a sound power level of 94.5 dB(A) can produce a steady-state sound pressure of 87 dB(A) due to the reverberant field only inside the room. Now, the existing equipment of this room generates a steady reverberant field of 83 dB(A). If 5 new machines having the same sound power level will be installed in the room, what is the allowable maximum sound power level for each machine so the noise level in the room does not exceed 88 dB(A)? Assume that the direct field is small compared to the reverberant field so that it can be ignored. Besides, the spectral content of noise from the new machines is similar to the existing noise.

Answer 1