Room acoustics extends pipe-mode analysis to many directions

Evidence

We have often spoken of air vibrations in pipes, wind instruments, or Helmholtz resonators. These have been treated as quasi-one-dimensional, in the sense that what matters is the nodes and air pressure variations along the axis of the pipe or instrument (figure 27.2, left). The sound pressure is approximately constant perpendicular to that axis. More generally, the nodes can lay in many directions inside a space. The transition from pipes to rooms begins with enlarging our repertoire of modes to include those shown on the right in figure 27.2. — Eric J. Heller, Why You Hear What You Hear- An…, 2426

Categorization

• DEFINE: Clarifies that room acoustics generalizes the quasi-1D modal analysis used for pipes into multi-directional modes.