I have the synthetic HootnStik. It sounds very good. I have had great luck using an owl call throughout the day We have so many crows and I think that's why a crow call is rarely effective on our lease. I will crow call with my mouth on occasion but I leave the crow call at home. I have had luck with a Quaker Boy Hawk Screamer.
One day we was hunting and an ambulance went by with their siren on and a gobbler went nuts gobbling at the siren. They also like the air brakes on 18 wheelers.