Simplify the following text for a Grade 9 native English-speaking person.
Original: The hurdy-gurdy 's strings are similarly set into vibration by means of a `` rosin wheel , '' a wooden wheel which contacts the strings as it is rotated by means of a crank handle , creating a `` bowed '' tone .
Simplified: The hurdy-gurdy , an instrument known in medieval Europe , has strings which are bowed by a `` rosin wheel , '' which is turned by a handle .