  Human categorization of sound seems predominantly based on sound source
properties. To estimate these source properties we propose a novel sound
analysis method, which separates sound into different sonic textures: tones,
pulses, and broadband noises. The audible presence of tones or pulses
corresponds to more extended cochleagram patterns than can be expected on the
basis of correlations introduced by the gammachirp filterbank alone. We design
tract features to respond to these extended patterns, and use these to identify
areas of the time-frequency plane as tonal, pulsal, and noisy. Where an area is
marked as noisy if it is neither tonal nor pulsal. To investigate whether a
similar separation indeed underlies human perceptual organization we introduce
tract based descriptors: tonality, pulsality, and noisiness. These descriptors
keep track of either the total energy or the cochleagram area marked as
respectively tonal, pulsal, and noisy. Energy based tonality and pulsality is
strongly correlated with the first perceptual dimension of human subjects,
while energy based noisiness correlates moderately with the second perceptual
dimension. We conclude that harmonic, impact and continuous process sounds can
be largely separated with energy based tonality, pulsality and noisiness.
