I was fooling around in World's End State Park one year with some roosted birds in the evening. I must have had 20 different birds screaming at me off the limb. I could hear a car coming down the gravel road for quite a ways, and he pulled over to ask me if I was the one with the owl call? I told him it was me, and he asked what call I was using because it sounded really good and he could hear it way off in the distance.
I let out a big Whooo..whooo...whooo..whoo.who.whooooooo.
Used to use my voice to owl hoot until I strained it one day owl hooting. Can't hoot worth a hoot now with my natural voice, but I do use just a plain old Primos Hooter and a an Ernie Fetters Holly Hooter.
Lohman Barred owl call. The loudest owl call I have ever used and it NEVER fails to shock a gobble when a crow call or peacock won't. Wish they still made them. I'm always looking on Ebay for one but it's been years since I've seen another one...