Every listening test has extraneous variables that must be controlled

Evidence

On each loudspeaker one set of technical measurements is sufficient, but subjective tests must be repeated and randomized, and must involve several listeners to be statistically useful data. — Toole, Floyd E, Sound reproduction- the acoustics and…, 144 (#expands, via linked claim)

Categorization

• XREF: connects to: Subjective listening tests require repetition and randomization to be statistically valid — Toole, Floyd E, Sound reproduction- the acoustics and…, 144; Pilot tests and controlled constants eliminate confounding in listening experiments; Randomizing identifiers, positions, and music prevents experimenter bias in listening tests (+1 more)

Broader Connections

• Room acoustics contaminate loudspeaker listening tests needing controlled environments #exemplifies (0.92)
• Subjective listening tests require repetition and randomization to be statistically valid #expands (0.88) — Toole, Floyd E, Sound reproduction- the acoustics and…, 144
• Pilot tests and controlled constants eliminate confounding in listening experiments #exemplifies (0.85)
• Randomizing identifiers, positions, and music prevents experimenter bias in listening tests #exemplifies (0.82)