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NEXTThe rate of depolarisation qualifies the sounds with respect to the fluctuations of their partials.
The rate of depolarisation is controlled by the capacitance value k. This value may vary from 0.01 to 10. We identified 3 different ranges of values, whose effect were perceptually distinctive. The results of runs with similar or close k values may overlap; sometimes they result in one type of sounds and sometimes in another type:
1. the range of the lower k values (from 0.01 to 2.6): in the lower range, the nerve cells tend to burn quickly and become permanently quiescent. Consequently, the sounds tend to begin with a short period of random fluctuation of its partials, followed by a permanent steady portion. The frequency of the steady portion corresponds to the value which was allocated to the quiescent state (that is n = 0)
2. the range of medium k values (from 2.61 to 7): when the value of k reaches the range of the medium values, most of the nerve cells become depolarised and tend to remain so. However, some quiescent cells may appear sporadically. The sounds in this case, tend to maintain their initial random fluctuation of partials; the fluctuation, however, may exhibit irregular oscillatory patterns towards the end of the sound
3. the range of the higher k values (from 7.1 to 10): once the value of k reaches the range of the high k values, the nerve cells tend to manifest regular oscillatory patterns of long durations at an increasing rate. The sounds of the higher range tend to begin with some irregular fluctuation and settle to a patterns of regular oscillatory fluctuation
The acoustic effect of the variation of the length of the sonic particles is as follows: shorter durations (for example, 35 milliseconds) produce various textures of sparkling, bubble-like cloud of sounds. Larger durations (for example, 1 second), on the other hand, produce sequences of "sound strokes", or pitches with timbre variation.
Chaosynth currently supports only the synchronous production of sound particles; all particles are of the same duration, they do not overlap and there is no silence between them. Further research is needed to study the effects of asynchronous synthesis.
The amount of oscillators and the dimension of the grid contribute to the spectral content and to the roughness of the spectral variation.
The amount of oscillators dictates the maximum number of partials in a particle; a larger number of partials produces a rich spectrum and consequently, a greater spectral fluctuation.
The frequency of each particle's partial is the result of the arithmetic mean of the frequency values attached to the states of nerve cells. The dimension of the grid therefore affects the degree of granulation of the spectral variation of the sound event; larger amounts of nerve cells per oscillator produces finer granulation effects, whilst a shorter amount produces coarser granulation effects.