Piano timbre would be unstable if we heard phase changes.

Evidence

Many investigators over many years attempted to determine whether phase shift mattered to sound quality (e.g. Hansen and Madsen, 1974a, 1974b; Lipshitz et al., 1982; Van Keulen, 1991; Greenfield and Hawksford, 1990). In every case it has been shown that, if it is audible, it is a subtle effect, most easily heard through headphones or in an anechoic chamber, using carefully chosen or contrived signals. There is quite general agreement that with music, reproduced through loudspeakers in normally reflective rooms phase shift is substantially or completely inaudible. When it has been audible as a difference, when it is switched in and out, it is not clear that listeners had a preference. — Toole, Floyd E, Sound reproduction- the acoustics and…, 972 (#corroborates, via linked claim)

Categorization

• XREF: connects to: Phase shift is largely inaudible for reproduced music in reflective rooms — Toole, Floyd E, Sound reproduction- the acoustics and…, 972; Acute phase sensitivity would make sound perception unusable across locations.; The ear cannot sense a tone’s absolute phase but does sense phase differences. (+1 more)

Broader Connections

• Phase shift is largely inaudible for reproduced music in reflective rooms #corroborates (0.85) — Toole, Floyd E, Sound reproduction- the acoustics and…, 972
• The ear cannot sense a tone’s absolute phase but does sense phase differences. #qualifies (0.85)
• Phase alignment creates a ‘buzzy’ timbre perceptible without room reflections #corroborates (0.80)
• Acute phase sensitivity would make sound perception unusable across locations. #expands (0.78)