What is making this noise?

You have me curious now - I live in the new part of Campoverde!  I haven’t heard this noise / sound.  Does it happen at a particular time of day and is it just this time of year?  Do you think it sounds more like an animal than a bird?

At first I thought it was a child playing, making whooping noises but realized it couldn't be as it goes on and on. It was making the noise this morning but has stopped now . I really can't tell if it's a bird or a dog or maybe even a machine??? It does sound more like a mournful cry than a noise a machine would make but who knows? It doesn't just happen in the mornings, it can be any time of the day. It bugs me because I can't pinpoint what it is! Definitely coming from the direction of Jumerca supermarket way, though like I said, sound travels in weird ways here and it could be coming from somewhere completely different. 

Does it repeat either three or four times, stop, and then repeat? If so, it's a hoopoe. If not, then I've no idea.

We live near Juanita's. The sound might be the little town hall cleaning truck. It has some sort of hybrid electric motor. When the brakes are applied, it squeels, and sometimes it sounds like a tube train slowing down. 

I haven't heard any strange animals around.

I was once told that that sort of noise indicated that the man who sharpens knives and scissors was in the area, although I have never seen him and his van 😊

The knife and scissors sharpening van has been round the area in the last few days. The noise that comes through the speaker sounds like someone blowing up and down a high-pitched plastic panpipe!

I also hear the same noise, which appears to come from across the fields on the opposite side Of the road to spar and Iceland.  It's quite a high pitch, but I'm used to it now, but have no idea what it is.  

Is there a wind blowing when you hear these noises, as we have an area where I live in Britain called the chasms, depending on which way the wind is blowing when it blows between the cracks in the cliff face it can sound like an injured dog howling, or a ghostly moan.

Hi, doesn't seem to be a set time for the noise but at the time of writing this 21.50 on Sunday night I can hear it, it's still coming from the same sort of direction, not as loud as usual but still there.