About a year ago I was listening to barred owls in my neighborhood so I went online and watched a few youtube videos. It turns out they are very territorial.
So I ripped the soundtrack from the youtube video and edited out the narrator and other background noise.
Then I loaded it onto my predator call.
It took about 20 seconds of play time for a pair of them to silently glide within about 15 feet of me when I turned on the call. I tried it again when I heard them last fall, to the same result. They landed on the electrical line directly above the call. I made no effort to hide myself, and they didn't seem to care. They stuck around long enough to watch me skin most of a raccoon.
They are bigger than you would expect, and their silent flight is really impressive.
If anyone here would like the sound file I put together, just email me at my username at yahoo.com It is an mp3 and would probably even work if you were to open the doors on your car and crank the radio. It is my observation that they aren't shy.
I've turned it on once when they weren't calling to see if I could bring them in, and I was not successful. I think you probably need to hear them talking before the call will attract their attention, but I haven't/won't ever use the call enough to be able to say that with certainty.