Speakers making buzzing sound

[Eclipsy]

Today, my speakers started making a buzzing noise, and I was wondering if this could be a bad thing or not.

It comes and goes, it stays for around 5-10 seconds then leaves for about an hour or so.

My speakers do continue making a buzzing sound if I turn the sound off.

 

[makkem]

Hi
This could be interference being transmitted through the speakers power supply.
The most common causes of this type of interference are fridges freezers and air conditioners and almost anything with a motor in and could be in your neighbors house.It can be a sign that the electrical filter in that appliance has failed.
The smoothing capacitors in your speaker power supply are obviously not removing this .