Vibrotactile Stimulation Can Affect Auditory Loudness: A Pilot Study

Abstract

Abstract. Very few cases have been reported where tactile stimulation affects auditory perception. In this pilot study, we asked volunteers to compare the loudness of combinations of vibrotactile and auditory stimuli. A 50-300 Hz band-limited pink noise signal was used as the stimulus in the two modalities, simultaneously heard through headphones and felt in the hands to be compared to when it was heard only. On average, the same auditory stimulus was judged to be about one dB louder when it was simultaneously heard and felt rather than when it was heard only. This condition could be interpreted as having enhanced the perception of loudness by a whole jnd.

Judged Consonance of Tactile and Auditory Frequencies

“…In our previous paper, we reported that the subjective auditory intensity, which is one of the basic perceptual attributes, becomes louder by adding tactile vibration using the same source as the sound [10].…”

Plucked String Stiffness Affects Loudness Perception

“…However, this response pattern was not observed when the standard was auditory. Although, in our case both standard and comparisons are always auditory-haptic, a condition not considered in [13], it remains unclear to what extent these kinds of response order effects played a role.…”

“…These kinds of biases are apparently complicated further by other factors such as sensory modality. For instance, Okazaki et al [13] tested a number of standard and comparison conditions. On half the conditions the standard was haptic and in the other the standard was auditory.…”

“…For instance, with pianists, the perceived loudness increased exponentially with the force applied on the piano keys [12]. More recently, Okazaki et al found that complex, broadband auditory stimuli tend to be perceived louder when the same signal was simultaneously heard and felt rather than when it was heard only [13]. Other results corroborated the effect of vibrotactile inputs on loudness perception, such as whole-body vibrations delivered through the chair while listening to a sound [14], or with irrelevant tactile, stimuli [15].…”

Perception of Vibrotactile Cues in Musical Performance

“…Overall, the results presented here suggest that research on active touch in musical performance may prove precious to understand the role, mechanisms, and prospective applications of active touch perception also outside the musical context. An example application that seems at immediate reach of current tactile interfaces is to create illusory effects of loudness change by varying the intensity of vibratory feedback [39,42].…”