High-pitched hum Dunstans Road/Dawsons Heights area

[Comeback Book Group]

Over the course of the past few days I've noticed a high-pitched "electrical" (for want of a better description) hum when I've been in my garden. I live on Dunstans Road, close to the Dawsons Heights area. It's hard to pinpoint the direction of the source - lots of building surfaces which deflect and reflect noise - but it would appear to be somewhere in the Donkey Alley/Hillcourt Road/Overhill Road area. It's not massively loud but neither do I need to strain to hear it...

Anyone else noticed it? Any idea as to the source?

[intexasatthe moment]

I don't know if it's any help but I've found that commercial air conditioning units can be the source of the kind of noise you describe .

[Penguin68]

There are a number of electricity transformers and sub stations locally. You might be hearing a reflected sound from those.

[Robert Poste's Child]

Anyone else remember this?

https://youtu.be/8Kkmf8zHqnU