HapticMic: Developing a Haptic-Enabled Microphone and Investigating the Impact of Persuasive Vibrations on Speakers in Real-World Conditions

Vibrotactile feedback is closely related to sound. When speaking, the body vibrates, and vibrations from external sound sources, such as loudspeakers, can be physically perceived when in close proximity. A preliminary study explored augmenting speech with synchronized vibrations, yielding promising results during speech-based interactions in virtual reality (VR). This concept has been named “Persuasive Vibrations,” as evidence shows positive effects on the speaker’s perceived persuasiveness when exposed to haptic feedback synchronized with their voice. This thesis work primarily focuses on the design and development of HapticMic: a haptic-enabled device that reinforces speech with real-time vibrotactile feedback synchronized with the speaker’s voice. Secondly, a user study involving 23 participants was conducted to evaluate the device and the effects of Persuasive Vibrations in a simulated real-life scenario under laboratory-induced stressors. Participants, all between 18 and 34 years old, were required to deliver a 2-minute speech in front of a senior jury, with limited preparation time, while speaking into the HapticMic. The experiment examined whether primitive psychological constructs, directly related to confidence and persuasion, were influenced by haptic feedback. Specifically state Communication Anxiety (state CA) and Self-Efficacy (SE) were investigated, measured through standardized questionnaires. Additionally, participants’ voices were recorded to extract acoustic features associated with confidence. External jury evaluations and qualitative participant feedback were also collected. Interestingly, qualitative analysis revealed that participants were evenly split into three groups: those who found the vibrations helpful, impairing, or neutral. However, quantitative analysis did not show statistically significant effects attributable to the haptic feedback, indicating that further explorations are needed.