I've only heard one roar and it's because we chased it down and bled it out, when we approached him he couldn't get up but he turned his head towards us on his front legs and roared...I highly doubt, and it didn't happen, that any bucks in ear shot of him would have come in. I honestly feel it will scare more deer than it will ever call in but it will probably call one in from time to time but that doesn't make me want one. I have numerous grunt tubes and don't need another because it "growls or roars", I can do that with a couple I already have but wouldn't. I'll hopefully hunt until I'm in my 80's, another 40 some years and I won't own a growl/roar call unless it's handed to me, even then it won't go with me to the woods. Sorry MADD/Primos guys, good marketing tho.