Life log system based on tactile sound

In this paper, we propose a new life log system which estimates touching object based on a contact sound. A life log system records our behaviors for recommending appropriate information depending on logs. There are some devices including a camera, a microphone and a GPS for recording our actions. However, those devices record too rich information to be accepted in terms of privacy. In this research we focus on the sound when we touch/manipulate objects. A piezoelectric device on a fingernail records touching sound propagating through a fingertip. Since the recorded sound depends on touching objects, we can record what we touched. This can be used as a new life log which assures secrecy. We show that our prototype system recognizes 12 different actions with 94.4% accuracy.