"Persuasive Vibrations": Studying the Influence of Vibration Parameters on Speech Persuasion

This paper investigates the notion of "Persuasive Vibrations", which showed that augmenting a person's speech with vibrotactile feedback could artificially increase persuasion. However, while the initial paper has shown the effect, the underlying reasons why vibrations enhance persuasion remain unknown. Through two different user studies, this paper aims to study how the underlying parameters of the vibratory feedback (e.g., frequency, amplitude, or audio-vibration synchronization) influence persuasion. The first study aimed to identify the parameters of vibrotactile feedback that can positively influence persuasion. The second study evaluated vibrotactile feedback that might impair the persuasive effect. In a nutshell, the first experiment suggests that the isolation of different properties of the vibratory signal could tend to provide higher persuasion compared to no vibratory feedback. A lower frequency at 100 Hz seems the most efficient way to generate a persuasive effect. In contrast, the second experiment suggests that some alteration of the vibratory signal (e.g., latency) does not decrease the levels of persuasion compared to the no-vibration condition. All in all, the results suggest that using lower frequencies could have a better effect on persuasion. These results could serve as a basis for haptic design in applications like videoconferencing, virtual meetings, and training systems where supporting user speech is essential.