During the spring, a gobbler may gobble at any loud noises. I say may, not will. It depends on how much hunting pressure has been on the birds. If a gobbler answered a crow call then 5 minutes later a hunter walks in on him, Mr. Gobbler will learn from that experience.
Crow calls, owl hoot calls, peacock imitators, all are used as "locator" calls.
I have not had great success with a crow call, but some hunters swear by them.
I have heard gobblers answer an owl's (a real one) hoot at daylight.
I have had good luck using a gobble call to locate birds later in the day after they have their hens.