  Text entry is a common activity in virtual reality (VR) systems. There is a
limited number of available hands-free techniques, which allow users to carry
out text entry when users' hands are busy such as holding items or hand-based
devices are not available. The most used hands-free text entry technique is
DwellType, where a user selects a letter by dwelling over it for a specific
period. However, its performance is limited due to the fixed dwell time for
each character selection. In this paper, we explore two other hands-free text
entry mechanisms in VR: BlinkType and NeckType, which leverage users' eye
blinks and neck's forward and backward movements to select letters. With a user
study, we compare the performance of the two techniques with DwellType. Results
show that users can achieve an average text entry rate of 13.47, 11.18 and
11.65 words per minute with BlinkType, NeckType, and DwellType, respectively.
Users' subjective feedback shows BlinkType as the preferred technique for text
entry in VR.
