CheekTouch combines tactile feedback delivered via the cheek and multi-finger input while speaking on the mobile phone. It is natural to use because it maintains the posture of speaking on the phone. Also, adding a tactile interface on the cheek can compensate for non-verbal cues on voice communi-cation. If another audio signal is added for non-verbal cue while speaking on the mobile phone, then it might disturb communication and overlap with verbal signals. Also, if video signals are added, users have to move their devices from their cheeks to see the visual messages which could lead to missing verbal signals. Therefore, tactile interfaces on the cheek can enrich communication while speaking on the mobile phone.
Source: CheekTouch: Park, Y., Lim, C., Nam, T. 2010, An Affective Interaction Technique while Speaking on the Mobile Phone. In Proceeding of Extended Abstracts on Human Factors in Computing Systems (CHI EA '10 CHI '10 ) 3241-3246
http://cidr.kaist.ac.kr/mediawiki/index.php/CheekTouch
