Sound requires a physical medium and is fundamentally a mechanical disturbance

Evidence

At a physical level, sound is simply a mechanical disturbance of the medium, which may be air, or a solid, liquid or other gas. However, such a simplistic description is not very useful, as it provides no information about the way this disturbance travels or any of its characteristics other than the requirement for a medium in order for it to propagate. What is required is a more accurate description that can be used to make predictions of the behavior of sound in a variety of contexts. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 49

At a physical level sound is simply a mechanical disturbance of the medium, which may be air, or a solid, liquid or other gas. However, such a simplistic description is not very useful as it provides no information about the way this disturbance travels, or any of its characteristics other than the requirement for a medium in order for it to propagate. What is required is a more accurate description which can be used to make predictions of the behavior of sound in a variety of contexts. — David Howard, Jamie Angus, coustics and Psychoacoustics, 23

Categorization

  • DEFINE: Establishes the core physical definition of sound as a medium-borne disturbance, foundational for all later psychoacoustic concepts.
  • corroborated: 6 independent passages support this claim — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 49; David Howard, Jamie Angus, coustics and Psychoacoustics, 23
  • XREF: connects to: Sound is a mechanical wave requiring a medium and a vibrating source; Sound propagation depends on interactions with objects and the medium — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 322

Broader Connections