Perceptually Correlated Parameters of Musical Instrument Tones

In Western music culture instruments have been developed according to unique
instrument acoustical features based on types of excitation, resonance, and radiation.
These include the woodwind, brass, bowed and plucked string, and percussion
families of instruments. On the other hand, instrument performance depends on
musical training, and music listening depends on perception of instrument output.
Since musical signals are easier to understand in the frequency domain than the time
domain, much effort has been made to perform spectral analysis and extract salient
parameters, such as spectral centroids, in order to create simplified synthesis models
for musical instrument sound synthesis. Moreover, perceptual tests have been made
to determine the relative importance of various parameters, such as spectral centroid
variation, spectral incoherence, and spectral irregularity. It turns out that the
importance of particular parameters depends on both their strengths within musical
sounds as well as the robustness of their effect on perception. Methods that the author
and his colleagues have used to explore timbre perception are: 1) discrimination
of parameter reduction or elimination; 2) dissimilarity judgments together with multidimensional
scaling; 3) informal listening to sound morphing examples. This paper
discusses ramifications of this work for sound synthesis and timbre transposition.