Timbre has no objective right answer and must be measured by averaged listener ratings

Evidence

Timbre judgments are highly subjective and therefore individualistic. Unlike pitch or loudness judgments, where listeners might be asked to rate sounds on scales of low to high or soft to loud respectively, there is no “right” answer for timbre judgments. Listeners will usually be asked to compare the timbre of different sounds and rate each numerically between two opposite extremes of descriptive adjectives, for example on a one to ten scale between “bright” (1)—“dark” (10) or “brilliant” (1)—“dull” (10), and a number of such descriptive adjective pairs could be rated for a particular sound. The average of ratings obtained from a number of listeners is often used to give a sound an overall timbral description. Hall (1991) suggests that it is theoretically possible that one day up to five specific rating scales could be “sufficient to accurately identify almost any timbre.” — David Howard, Jamie Angus, coustics and Psychoacoustics, 1505

Categorization

• DEFINE: Explains how timbre differs from pitch and loudness as a subjective quality, and the standard numeric rating-scale method used to describe it.
• XREF: Connects to psychoacoustics’ broader theme that perception is constructed and subjective rather than a faithful copy of the physical signal. — connects to: Timbre is judged subjectively with no right answer, unlike pitch or loudness — David Howard, Jamie Angus, coustics and Psychoacoustics, 1505
• QUESTION: Which five rating scales does Hall propose as sufficient for any timbre? Worth chasing down.