Direct sound intensity falls with the square of distance from the source
Evidence
Equation 6.1 shows that the intensity of the direct sound reduces as the square of the distance from the source, in the same way as a sound in free space. This has important consequences for listening to sound in real spaces. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1691
However, it is important to remember that the sound intensity of a source reduces in proportion to the square of the distance, irrespective of the directivity. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 319
Categorization
- XREF: Anchors the inverse-square law introduced in Chapter 1, the physical basis for why close seating in a concert hall sounds so different from the back rows. — connects to: Downwind sound is bent downward and waveguides along the ground, gaining intensity; Sound pressure amplitude falls off as the inverse of distance from a source; Sound intensity falls off as distance squares only in free field, boundary-free conditions (+5 more)
- DEFINE: Clarifies what ‘direct sound’ means physically: the unreflected component that behaves like free-space radiation.
- corroborated: 4 independent passages support this claim — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1691; David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 319