Reverberation calculations break down for tunnel-like room shapes.

Evidence

The concept of a mean free path is valid. Again, this is required in order to have an average absorption coefficient, but in addition, it means that the room’s shape must not be too extreme. This means that this analysis is not valid for rooms that resemble long tunnels. However, most real rooms are not too deviant, and the mean free path equation is applicable. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1837

Categorization

• XREF: connects to: Extreme room shapes break reverberation-field formulas because sound visits surfaces unevenly — David Howard, Jamie Angus, coustics and Psychoacoustics, 1811; Physical room constraints can make ideal reverberation targets unattainable — David Howard, Jamie Angus, coustics and Psychoacoustics, 1958