Room acoustics act as another system modifying the instrument’s output

Evidence

Waterhouse (1955) extended work by Rayleigh (1964) and confirmed experimentally that the power output of a source is affected by the presence of boundaries, for example the walls in a room. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2134 (#expands, via linked claim)

Categorization

• XREF: connects to: Shared room acoustics let 1920 phonograph demos fool live audiences; Room acoustics contaminate loudspeaker listening tests needing controlled environments; Loudspeakers and rooms function together as a single audible system (+10 more)

Broader Connections

• Room boundaries alter a sound source’s radiated power, not just its perceived sound #expands (0.90) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2134
• Room boundaries alter loudspeaker output through reflected image sources #expands (0.85)