Central to the concern of modern psychophysics is the notion of perceptualjudgemental relativity, contrary to the mainstream and more traditional approach of sensory psychophysics during the nineteenth and twentieth centuries. Take for example the loudness of familiar sounds varying in intensity, say from the absolute threshold of hearing to the painful noise of a jet plane take-off. Although the variable acoustic events are consciously experienced as “absolute” they are in fact “relative” to their immediately given contextual background, at least partly. In general, humans and other animals do not directly identify single stimuli but compare each stimulus event in relation to other stimuli, all of which involve both simultaneous and successive (sequential) comparison processes beyond simple sensory event recording. Psychophysical judgement is, therefore, a complex task, which is nowadays better understood through the combined use of different but interrelated perceptual-cognitive paradigms.