Hello, I have tried plugging this headphones set in different sound sources (phone, CD player, TV) but the result is the same: the music is always heard with a loud static noise in the background. The batteries seem to be new and the charge adequate. Please see the picture of the device make/model.

I would greatly appreciate any suggestion on where to start my troubleshooting, or a reference to an online resource which could help. Trying to fix this for my neighbor.

As always, thanks and best wishes, h.

When I hear that in my headphones that means that the wires in the headphones are separating from the jack that connects to the actual device. I would definitely go for a new pair because they will probably die on you soon.

900mhz could be your problem. There is a lot of interference in the 900mhz range. I had portable phones that worked in that frequency and even fluorescent lights would make it hum. There may be something causing interference...maybe a portable phone. I would unplug any wireless devices and shut off fluorescent lights until you find the noise.