Yes. It can happen. Sound waves travel in the body as well, so some people can hear these things when they happen, just like people hear their own heartbeat.
Absolutely. I have had patients tell me that their tendon tears have sounded like a gun going off, a loud pop, a snap, etc. These tendon tears have included rotator cuff, pectoralis major, triceps, biceps, hamstrings, quads, patellar, and achilles.