PRINCIPALI GRANDEZZE ACUSTICHE - Studium

Combining coherent acoustic signals• Two acoustic signals of Rms pressures 1Pa are, at a given position, are inphase.• What are the sound pressure levels of each wave and of the combined wave?• Total Rms pressure P T= 1 + 1 = 2Pa⎛ 1 ⎞L1 20×Log10⎜ ⎟ = 94 dB5⎝ 2×10 ⎠=⎛ 2 ⎞∴ L LogdB− T= 20×10 ⎜ ⎟ = 100−5⎝ 2×10 ⎠When waves are in phase and are of equal amplitude there is an increase of 6 dBin the sound pressure level.This occurs, i.e., when waves are reflected off a hard surface – say a wall.