I have never called in a lion....only coyotes and a bobcat. But, as a houndsman who chases them all winter, I can attest that you can spend a lot of time calling into an area that has no lion to hear you. Spend some time in the snow looking for fresh tracks, and call into that area.
That’s the battle, especially here in western Oregon where we don’t ever have snow to cut/age tracks, and the thick vegetation killing the sound of the call
I think they are very easy to call in, it’s just difficult to get within ear shot
I do have several places that I know are travel corridors for lions, so that’s how I approach it, walk those areas out looking for tracks and scrapes, then age the sign as well as I can, then anticipate where they might be now.
Last winter I was able to stay on a track for 3.8 miles with no snow, he covered that ground in under 12hrs for sure, probably quite a bit under, but I was in there the night before, his track was made after I left, and before daylight the next morning
It was cold, so I wasn’t going to stop and call until I felt like I was close… when I did finally do a setup, I think I was pretty close to that cat, but obviously not close enough