Teodor Künnapas

Acoustic perception and acoustic memory of letters : Multidimensional ratio scaling and multidimensional similarity

Abstract The similarities in acoustic perception and acoustic memory, respectively, of nine letters of the alphabet were studied by direct multidimensional ratio scaling and by the method of multidimensional similarity analysis. Three factors were found which were exactly the same in respect of both perception and memory of these letters, and with nearly identical loadings.

Interindividual differences in homomodal and heteromodal scaling

Abstract Thirty-two subjects participated in eight experiments concerning the intensity and duration of auditory and vibrotactile stimulation. Individual scales were obtained for each subject in each experimental condition by the method of magnitude estimation. The standards were either of the same modality as the comparison stimuli (homomodal) or different modality from the comparison stimulai (heteromodal). It was found (1) that a power function in its simplest form gave satisfactory description of the relation between the stimulus and subjective intensity or subjective duration in all cases, (2) that about 70% of the interindividual variability could be accouonted for by three homogeneous clusters, (3) that the correlations between the exponents over individuals in eight conditions seem to depend on intensity or duration, and on homomodal or heteromodal scaling, and (4) that percieved duration seems to be a more stabile attribute than intensity.

Monochromatic Brightness Functions

SUMMARYBy means of a method of ratio estimation, scale values were obtained for the subjective brightness of various physical intensities of monochromatic light characterized by wave lengths 459, 471, 527, 554, 595, 627 and 672 mμ.The brightness functions were studieed by plotting the scale values against stimulus intensity for each wave length. The curves for 459, 471 and 672 mμ exhibited a sigmoid form, indicating that a probability function may be involved in the function relating brightness to stimulus intensity for these wave lengths. The trend of the other curves was negatively accelerated, but it is possible that an inflexion point may be located below the experimental range.The difference in form between the brightness functions can explain certain empirical relations between brightness, hue and saturation.