Modal Solutions for the Sound in Enclosures

While the integral equation approach of determining the sound field described in the previous sections is very general and applicable to a wide range of domain shapes, it rarely leads to equations that are simple enough to provide insight into the nature of the sound field; the results must be obtained numerically. For harmonic sound fields, when the amplitude of the pressure is examined as a function of frequency, one often finds sharp peaks and dips that are very similar to those due to resonances in vibrating structures.