Question

Which device converts mechanical energy to sound energy?

Answer 1

musical instruments like bowing of a violin,
plucking of a guitar , striking of a piano
hope it helps you

Answer 2

musical instruments like bowing of a violin and plucking of a guitar as mechanical energy is associated with the motion and position of the object so eg. when a guitar string is pluck it creates vibration in the air by its mean position and thus the vibration creates sound and so mechanical energy is converted to sound energy in musical instruments