Hi!! Thank you for your answer.Welcome to the forums, newcomer!
Are you sure the noise is coming from the PSU's end and not from a fan or a component on the rest of the platform/system? Use a sheet of A4 paper and roll it into a tube and hold one end of the tube to your ear, while the other is used to inspect for the source of the sound.
You might want to relocate to another wall outlet in your residence.