That’s an ONT , and they don’t make any noise , there is nothing inside to make a noise , obviously if there were a fault , a solid state device breaking down , like a resistor, capacitor, ( that type of thing ) it could potentially make a noise but it likely would also smell of burning , and not actually work for long before failing.
TBH, considering the somewhat overloaded extension lead with the ONT power adapter and other devices connected, that’s a more likely source of any ‘ electrical ’ noise , you probably should start with a ‘clean’ power supply to the ONT adapter ( disconnecting everything else ) to see if that helps , also it’s can’t possibly be you can also ‘hear’ your neighbours ONT on the other side of a house wall , that’s also accepting the incredibly unlikely possibility that both your and your neighbours ONT are making a noise in the first place .
As stated previously, if the ‘noise’ is external and its wind noise as air passes over the cable , not much can be done about that , although the cable attaches quite close to the gutter, it may ‘drum’ on the gutter , but that would be if it moves around significantly in high winds , and you say the noise is not weather dependent
