Читать книгу Engineering Acoustics - Malcolm J. Crocker - Страница 113

1 If a constant‐volume velocity source of sound power level 120 dB (which is equivalent to 1 acoustic watt) radiates to whole space and it has a directivity factor of 12 at 50 m, what is the sound pressure level in that direction?

2 If this constant‐volume velocity source is put very near a hard reflecting floor, what will its sound pressure level be in the same direction?