I’ll not sure it had to make any sound.

All you had to do to silence the handshake was to send the command ATM0 down the serial line before dialing. The sound, visualized and explained

“Osteo-odonto-keratoprosthesis also known as “tooth in eye” surgery, is a medical procedure to restore vision in the most severe cases of corneal and ocular surface patients. It includes removal of a tooth from the patient or a donor.” Essentially, your tooth is implanted in your cheek and once it grows a new blood supply it’s taken out and put in your eye to replace a bad cornea. Wikipedia