Timbre is a residual category masking distinct sensations like sharpness and sensory pleasantness.

Evidence

Previously, there has been a tendency to transfer everything in steady-state sounds not related to the sensations of loudness or pitch, to a residual basket of sensations called timbre. Using this definition of timbre, it is necessary to extract from the mixture of sensations those that may be important. The sensation of “sharpness”, which may be related to what is called “density”, seems to be one of these. Closely related to sharpness, however inversely, is a sensation called sensory pleasantness. This sensation, however, also depends on other sensations such as roughness, loudness, and tonalness. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1339

Categorization

• DEFINE: Defines sharpness, sensory pleasantness, and reframes timbre as a residual category.