According to Federal Reserve Staff Interpretations, a signature is not required. See
this .
Q14(b)-4: Acknowledgment of receipt. Must the cosigner notice be signed by the cosigner?
A: The rule does not require that the cosigner sign the cosigner notice, or otherwise acknowledge its receipt. (See, however, Q14(b)-9 on permissible additions to the cosigner notice.)
HOWEVER, your bank may very well require a signature as part of its process and you would be in violation of that policy or procedure.