  We propose a method that stimulates musical vibration (generated from and
synchronized with musical signals), modulated by the direction and distance to
the target, on both sides of a user's neck with Hapbeat, a necklace-type haptic
device.We conducted three experiments to confirm that the proposed method can
achieve both haptic navigation and enhance the music-listening
experience.Experiment 1 consisted of conducting a questionnaire survey to
examine the effect of stimulating musical vibrations.Experiment 2 evaluated the
accuracy (deg) of users' ability to adjust their direction toward a target
using the proposed method.Experiment 3 examined the ability of four different
navigation methods by performing navigation tasks in a virtual environment.The
results of the experiments showed that stimulating musical vibration enhanced
the music-listening experience, and that the proposed method is able to provide
sufficient information to guide the users: accuracy in identifying directions
was about 20 deg, participants reached the target in all navigation tasks, and
in about 80% of all trials participants reached the target using the shortest
route.Furthermore, the proposed method succeeded in conveying distance
information, and Hapbeat can be combined with conventional navigation methods
without interfering with music listening.
