Multimodal Augmented Reality - Augmenting Auditory-Tactile Feedback to Change the Perception of Thickness

With vision being a primary sense of humans, we often first estimate the physical properties of objects by looking at them. However, when in doubt, for example, about the material they are made of or its structure, it is natural to apply other senses, such as haptics by touching them. Aiming at the ultimate goal of achieving a full-sensory augmented reality experience, we present an initial study focusing on multimodal feedback when tapping an object to estimate the thickness of its material. Our results indicate that we can change the perception of thickness of stiff objects by modulating acoustic stimuli. For flexible objects, which have a more distinctive tactile characteristic, adding vibratory responses when tapping on thick objects can make people perceive them as thin. We also identified that in the latter case, adding congruent acoustic stimuli does not further enhance the illusion but worsens it.