A Pseudo-Haptic Method Using Auditory Feedback: The Role of Delay, Frequency, and Loudness of Auditory Feedback in Response to a User's Button Click in Causing a Sensation of Heaviness

One of the important challenges in the field of haptic engineering is the development of methods to present haptic information on commonly-used information devices equipped only with screens and speakers. Earlier research has proposed the so-called "pseudo-haptic" method that can give users haptic impressions by modulating the visual feedback provided in response to user inputs. In this study, to extend the applicability of the pseudo-haptic method to devices without a screen, we propose a novel method for varying the heaviness sensation experienced by users by modulating auditory (as opposed to visual) feedback provided in response to user inputs. In this method, we manipulated the delay, frequency, and loudness of auditory feedback (a pure tone) given in response to the user clicking a button. Through a series of psychophysical experiments, we found that participants tended to report a stronger heaviness sensation when a pure tone was presented with a longer delay, lower frequency, and/or greater loudness. By manipulating the onset and offset timing of a pure tone, we also demonstrated that the delay of the offset of the pure tone, rather than that of its onset, was critical to the heaviness sensation. Our sound-based pseudo-haptic method can be implemented in information devices that can present auditory information, regardless of whether they can also present visual information or not.