What is the best dying rabbit/rabbit in distress call. I am using it for bears and coyotes.

I have a Flextone Dying Rabbit call, but it sounds bad sometimes. For those of u who dont know what it is, it has a rubber end where the sound comes out so u can squeeze it closed to muffle the call and make it lower to coax predators, and just leave it open for long distance calling. When i just leave it open though it doesnt sound at all like it does when i close the end.I listened to what the call should sound like and that what it sounds like when i close the end. The long distance calling almost sounds like a duck that squeels sometimes. Are there better calls out there or is that what its supposed to sound like?