Standing waves are a subclass of the more general phenomenon called resonant modes

Evidence

Strictly speaking, the standing waves we are discussing here should be called resonant modes. This is because it is possible to set up a standing wave without the use of two boundaries. For example, one could use two loudspeakers spaced apart and no boundaries to get a standing wave at discrete frequencies. One can do the same with one loudspeaker, or sound source, and one boundary. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 401

Categorization

Category: Definitional Content

• DEFINE: Terminological precision: distinguishes true standing waves (needing two boundaries) from the broader resonant-mode concept.
• QUESTION: Worth chasing: which everyday listening situations create resonant modes without two reflecting boundaries, and how does that change what we hear?

Related

• Standing waves can form without two bounding reflectors (similarity 0.91)
• A standing wave is still moving at normal speed while appearing stationary (similarity 0.87)
• Sound waves reflecting between two boundaries can form standing waves (similarity 0.85)
• Standing waves form when wavelengths match room dimensions (similarity 0.85)
• Standing waves occur at all multiples of the lowest resonant frequency (similarity 0.84)
• Standing waves arise from counter-propagating reflections with no net energy flow (similarity 0.84)
• Acoustic standing waves are termed modes with numbered order by frequency (similarity 0.83)
• Room standing waves cause sound pressure to vary with listening position (similarity 0.81)
• Opposing waves cancel only momentarily because energy persists in kinetic form (similarity 0.80)
• Every wave mode is simultaneously an oscillator depending on viewpoint (similarity 0.80)
• Room resonances occur at frequencies where whole numbers of wavelengths fit between surfaces (similarity 0.80)
• Standing waves create loudness dips at room midpoints (similarity 0.80)
• Standing-wave thinking applies only at low frequencies in small rooms (similarity 0.80)
• Room standing waves mask the adjacent-boundary effect even after averaging. (similarity 0.79)
• Acoustic waves reflect at discontinuities in tract area (similarity 0.79)