The human perception of the intensity of sound and light approximates the logarithm of intensity rather than a linear relationship ( Weber Fechner law ), making the dB scale a useful measure.
12.
Another key difference is that Weber's law and the LCJ involve proportions of comparisons in which one stimulus is judged greater than another whereas the so-called Weber-Fechner law does not.
13.
The rationale behind this is that a small difference is negligible if the average luminance is high, while the same small difference matters if the average luminance is low ( see Weber Fechner law ).
14.
In Pogson's time this was thought to be true ( see Weber Fechner law ), but it is now believed that the response is a power law ( see Stevens'power law ).
15.
No consideration is needed of possible nonlinearities such as the Weber-Fechner law, potential noise in the system, continuously varying angles at the joints, and many other factors that could afflict performance if this were a simple linear model.
16.
Thus time perception is like the perception of lights, sounds, and other sensory events, where accuracy also is relative to the size ( brightness, loudness, etc . ) of the percept being judged . ( See Weber-Fechner law .)
17.
In addition, Thurstone employed the approach to clarify other similarities and differences between Weber's law, the Weber-Fechner law, and the LCJ . An important clarification is that the LCJ does not " necessarily " involve a physical stimulus, whereas the other'laws'do.
18.
Thurstone showed that in terms of his conceptual framework, Weber's law and the so-called Weber-Fechner law, which are generally regarded as one and the same, are independent, in the sense that one may be applicable but not the other to a given collection of experimental data.
19.
In terms of Thurstone's conceptual framework, the association posited between perceived stimulus intensity and the physical magnitude of the stimulus in the Weber-Fechner law will only hold when Weber's law holds " and " the just noticeable difference ( JND ) is treated as a unit of measurement.
