The cymbalum may be regarded as a kind of clavichord (of the piano family), except that it has no keys. The musician uses sticks to trigger the strings, which are mounted on a soundboard. Also see the dulcimer.
The instrument is depicted in the 1100s in Persia, but it is possible that it originated even earlier - some speculate as long as about 2000 years ago.
Source:
http://www.vitrifolk.be/instruments/instruments-cymbalum-final2.html
http://www.cyrildupuy.com/diecimbalisten.php?page=iordache
http://www.youtube.com/watch?v=fRikKg04gGI&feature=relmfu
http://www.youtube.com/watch?v=w2ceWrIKfgA&feature=youtu.be