Potential long eared owl chicks in unusual place?!

Hi all, 

I wonder if anyone can help. I live above a river with bushes on the far side. On the edge of a Northern English city centre. I won't put further details just in case these are actually long eared owls I'm hearing.

For a few weeks I've been hearing the sound of a juvenile bird which I don't recognise. We have a lot of gulls, moorhens, ducks, terns which I am used to, but had never heard this one before. It sounds like it is coming from the bushes across the river.

I used a sound identifier which immediately identified it as a juvenile long eared owl. I have since been listening to lots of recordings on Youtube etc and it sounds identical. 

I just can't believe that such a magnificent (and I think not that common) bird could be nesting on a busy river path next to the city. 

Are there any other birds that have identical calls? Would be interested to hear some thoughts. 

Thank you!