There has been a long history in electrical muscle stimulation (EMS), which
has been used for medical and interaction purposes. Human-computer interaction
(HCI) researchers are now working on various applications, including virtual
reality (VR), notification, and learning. For the electric signals applied to
the human body, various types of waveforms have been considered and tested. In
typical applications, pulses with short duration are applied, however, many
perspectives are required to be considered. In addition to the duration and
polarity of the pulse/waves, the wave shapes can also be an essential factor to
consider. A problem of conventional EMS toolkits and systems are that they have
a limitation to the variety of signals that it can produce. For example, some
may be limited to monophonic pulses. Furthermore, they are usually limited to
rectangular pulses and a limited range of frequencies, and other waveforms
cannot be produced. These kinds of limitations make us challenging to consider
variations of EMS signals in HCI research and applications. The purpose of
"{\it wavEMS}" is to encourage testing of a variety of waveforms for EMS, which
can be manipulated through audio output. We believe that this can help improve
HCI applications, and to open up new application areas.