Free space requires unobstructed propagation in all directions
Evidence
Free space is a region in which the sound wave is free to travel in any direction. That is, there are no obstructions or changes in the propagation medium to affect its travel. Therefore, free space is a form of unbounded region. However, not all bounded regions are free space. For example, the wave may be coming out of a tube in a very large wall. In this case, there is a transition between a bounded and an unbounded region, but it is not free space because the wave cannot propagate in all directions. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 362
Free space is a region in which the sound wave is free to travel in any direction. That is, there are no obstructions or changes in the propagation medium to affect its travel. Therefore, free space is a form of unbounded region. However, not all bounded regions are free space. For example, the wave may be coming out of a tube in a very large wall. In this case there is a transition between a bounded and an unbounded region but it is not free space, because the wave cannot propagate in all directions. — David Howard, Jamie Angus, coustics and Psychoacoustics, 355
Categorization
- DEFINE: Sharply delimits the term ‘free space’ against merely unbounded regions, a distinction foundational for later radiation models.
- corroborated: 4 independent passages support this claim — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 362; David Howard, Jamie Angus, coustics and Psychoacoustics, 355