Exploring User-Defined Gestures as Input for Hearables and Recognizing of Ear-Touch Gestures by IMUs

Hearables are highly functional earphone-type wearables; however, existing input methods using stand-alone hearables are limited in the number of commands, and there is a need to extend device operation through hand gestures. In previous research on hearables for hand input, user understanding and gesture recognition systems have been developed. However, in the realm of user understanding, exploration remains incomplete concerning hand input with hearables, and extant recognition systems have not demonstrated proficiency in discerning user-defined gestures. In this study, we conducted a gesture elicitation study (GES) assuming hand input using hearables under six conditions (three interaction areas × two device shapes). Then, we extracted ear-touch gestures that the device's built-in IMU sensor could recognize from the user-defined gestures and investigated recognition performance. The results of the experiments in a sitting experiment showed that the gesture recognition rate for in-ear devices was 91.0%, and for ear-hook devices was 74.7%.