Timbre lacks a one-dimensional subjective scale unlike pitch and loudness

Evidence

There is no subjective rating scale against which timbre judgments can be made, unlike pitch and loudness which can, on average, be reliably rated by listeners on scales from “high” to “low.” The commonly quoted American National Standards Institute formal definition of timbre reflects this: “Timbre is that attribute of auditory sensation in terms of which a listener can judge two sounds similarly presented and having the same loudness and pitch as being dissimilar” (ANSI, 1960). In other words, two sounds that are perceived as being different but that have the same perceived loudness and pitch differ by virtue of their timbre (consider the examples on track 62 of the accompanying CD). — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1425

Pitch and loudness have one-dimensional subjective scales from “low” to “high” that can be related fairly directly to physical changes which can be measured, but timbre has no such one-dimensional subjective scale. — David Howard, Jamie Angus, coustics and Psychoacoustics, 1511

A note from any acoustic musical instrument typically changes dynamically throughout in its pitch, loudness and timbre. Pitch and loudness have one-dimensional subjective scales from “low” to “high” that can be related fairly directly to physical changes that can be measured, but timbre has no such one-dimensional subjective scale. Methods have been proposed to track the dynamic nature of timbre based on the manner in which the harmonic content of a sound changes throughout. The “tristimulus diagram” described by Pollard and Jansson (1982) is one such method in which the time course of individual notes is plotted on a triangular graph such as the example plotted in Figure 5.6. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1487

A note from any acoustic musical instrument typically changes dynamically throughout in its pitch, loudness and timbre. Pitch and loudness have one-dimensional subjective scales from “low” to “high” that can be related fairly directly to physical changes that can be measured, but timbre has no such one-dimensional subjective scale. Methods have been proposed to track the dynamic nature of timbre based on the manner in which the harmonic content of a sound changes throughout. The “tristimulus diagram” described by Pollard and Jansson (1982) is one such method in which the time course of individual notes is plotted on a triangular graph such as the example plotted in Figure 5.6. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1487

Categorization

• DEFINE: States the ANSI’s formal, definition-by-difference definition of timbre — central terminology for the reader’s psychoacoustic understanding.
• XREF: Echoes the negative-definition style familiar from other sensory attributes (e.g., color defined as what remains when lightness and hue are equal) and from how the reader’s noise/silence reading defined silence by contrast. — connects to: Timbre served as a residual basket for non-loudness non-pitch sensations — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1339; No musical tuning system can be proven superior to another; Pitch lacks magnitude, so rating scales fail where loudness scales succeed (+8 more)
• QUESTION: Why exactly can timbre never be rated on any scale? Worth chasing the perceptual research on why no consistent timbre dimension emerges from listener ratings.
• corroborated: 5 independent passages support this claim — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1425; David Howard, Jamie Angus, coustics and Psychoacoustics, 1511; David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1487

Broader Connections

• Perceived loudness and physical sound intensity follow different, non-intuitive mathematical scales #expands (0.75) — George Michelsen Foy, Zero Decibels, 53
• Pitch strength is a distinct perceptual dimension absent from loudness #contradicts (0.75) — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 1248
• Perceived loudness does not map one-to-one onto acoustic amplitude #expands (0.75) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 616