View your list of saved words. (You can log in using Facebook.)
Branch of psychology concerned with the effect of physical stimuli (such as sound waves) on mental processes. Psychophysics was established by Gustav Theodor Fechner in the mid-19th century, and since then its central inquiry has remained the quantitative relation between stimulus and sensation. A key tenet has been Weber's law. Psychophysical methods are used today in vision research and audiology, psychological testing, and commercial product comparisons (e.g., tobacco, perfume, and liquor).
This entry comes from Encyclopædia Britannica Concise. For the full entry on psychophysics, visit Britannica.com.