A comparison between the growths of loudness of vibrotactile pulse and sinusoidal stimuli

Abstract

The growths of loudness of pulsatile and sinusoidal stimuli were examined by the method of absolute magnitude estimation. Fourteen observers judged 32‐pps pulse and 250‐Hz sine stimuli on two sites on the palm: the thenar and hypothenar eminences. Estimates revealed that pulse stimuli were perceived as being louder than the sine stimuli on both sites. Power functions fit to the sine data had exponents of 0.84, while those fit to the upper limbs of the pulse data had slopes of 0.82. Cross‐quality matches between the two types of stimuli were made by nine of these observers. The group matches were not found to be internally consistent. That is, those made when the sine was the standard were not equivalent to matches made when the pulse was the standard. Such consistency was apparent, however, in some individual observer's data. In addition, slopes of matching functions were often well predicted by magnitude estimates using a procedure based upon the absolute scaling hypothesis. Intercepts were also predicted in some individual cases. [Work supported by NANCDS.]