Most psychophysical scales for time intervals are described by Stevens' Law, that relates the physical magnitude of a stimulus to its perceived magnitude as perceptual-time = a-constant.physical-time^b-constant. The b value differs from one dimension to the other. For time duration b is commonly found to be 1.1, slightly over estimation of the interval. However, for intervals shorter than 500 ms it is found that b is around 0.5, the square root of its physical duration (Michon, 1975).
Humans seem to have a relatively poor ability for time discrimination of intervals presented without context. The just notable differences (JND) are in the range of 5-10% (Woodrow, 1951) with an optimum near 600 ms intervals. However, in the context of a steady beat, the JND's are around 3% with the same optimum interval (Povel, 1981).
Much research was done on the existence of a spontaneous tempo, preferred rate or natural pace (Fraisse, 1982). This tempo should occur as a preferred rate of spontaneous tapping, and material presented at that rate should be easy to perceive and remember. There is weak, but converging evidence for the existence of such a rate, again with intervals around 600 ms. There is no consistent evidence for physiological correlates like heart rate.
There has been quite some research done on the influence of different dimensions on time perception, mainly in the fifties. Evidence was found that, in general, the higher pitched the sound the longer the percept (Cohen et al., 1954), and the same holds for louder sounds (Hirsch et al, 1956). Evenly divided intervals seem longer than irregular divided ones (Ornstein 1969).
Time intervals shorter then 120 ms, preceded by a physically shorter neighbour time interval, are underestimated to such a remarkable degree that one can speak of an auditory illusion (Nakajima et al., 1989).