Any mechanically vibrating surface can radiate acoustic waves. As in the case of electromagnetic waves, it is easiest to understand a point source first, and then to superimpose such radiators in comb...Any mechanically vibrating surface can radiate acoustic waves. As in the case of electromagnetic waves, it is easiest to understand a point source first, and then to superimpose such radiators in combinations that yield the total desired radiation pattern. Reciprocity applies to linear acoustics, so the receiving and transmitting properties of acoustic antennas are proportional, as they are for electromagnetic waves.
