When a fired projectile come into contact with a surface at a low angle of attack it will ricochet. The angular momentum of the projectile is changed after the contact.
These are the different ways a ricochet projectile could behave due to the change of angular momentum:
As the way the projectile fly through the air is changed, the sound it make during its’ travel is also changed. It would be cool if ricochet projectile have similar sound design to these examples:
Youtube: Ricochet sound from the movie Fury
Youtube: Ricochet sound from Squad 44