The procedure was as follows: An examiner sets a time of
the smart phone and hands it to a participant. The participant
flicks their finger on the screen toward left or right and
then orally answers the number corresponding to the hour
or minute. Each participant was prompted at least twice for
each number. If their first answer was different from the
second answer, the participant was prompted to answer a
third time. We defined success as two consecutive correct
answers or two correct answers out of three answers. In a preexperiment
practice session, participants were prompted with
vibrations corresponding to 16:08. We selected 16:08 because
these numbers can be recognized easily and the vibration of
these numbers includes both short and long vibrations. Each
participant was tested five times. TABLE II shows the results.
Nine participants were each prompted with two vibration
sequences — hour and minute — for each of the five test times.
Therefore, the total number of tests was 90. Participants made
only four errors, thus achieving a success rate of 86/90=95.5%.
The errors are shown Table III. The errors include feeling
a long vibration as a short vibration or mistaking four short