Design for Sharing Emotional Touches during Phone Calls: A Quantitative Evaluation of Four Tactile Representations

Abstract

Background As the importance of mobile phones as an emotional communication medium is growing, non-verbal behaviors such as facial expressions, touching behaviors and gestures ought to be considered to enhance phone conversations. Among various non-verbal signals, we focus on sharing specific touches that could be used for exchanging contextual and emotional cues. Along with this, to make the new phone conversation involving touching more natural, we consider maintaining natural audio conversation with phones by keeping the receiver on the ear and the transmitter on the mouth while holding the phone to the cheek. Methods In this paper, we focus on investigating ways to deliver four touches: pat, slap, tickle and kiss with sound and tactile feedback while holding the phone to the cheek as in typical phone calls. The interaction technique is called CheekTouch, and it is based on enabling users to share touches by representing finger gestures on one phone screen to the other party’s cheek using a vibrotactile display and sound stimulations. We asked the 30 students who participated to put the device on their cheek and wear earphones, and we provided them with 24 different stimulations. Results An evaluation was conducted to propose the most appropriate type of stimulation to deliver a pat, slap, tickle and kiss using CheekTouch. We showed that the best way to deliver a pat was to use a vibrotactile display combined with sound; however, a tickle was best delivered with only the vibrotactile display. A kiss and slap, on the other hand, were best delivered when there was only sound. Conclusions Considering the trends in sharing delicate emotions during phone-mediated communications, it is significant to investigate ways to convey touches during phone conversations beyond sharing visual emoticons. Here, we focused on findings ways to pat, slap, tickle and kiss by using existing phone technologies (vibrotactile motors and sound). Through the quantitative evaluation of those four touches, we discovered which stimulation type is best for delivering each of the touches. The results do not show whether those touches can deliver emotions, however, we believe CheekTouch and the findings from the evaluation can be used for sharing different types of non-verbal signals during audio-based phone conversations and enable further studies in the field of remote tactile interaction.