Recently I was listening to music on my headphones and noticed the sound had gone funny. It is not the headphones as I have tried several pairs. I have also run Dell test using the F12 button and the only problem I found was with the microphone test but I didn't care about that. I am putting my headphones in the correct slot. I checked. It is either the software or hardware. I removed Realtek and downloaded again and still same problem. I have googled this a lot and found someone else with a similar problem and they referred to it as sounding like Chipmunks. I guess it could be like that. Certainly one half of the sound is missing. I can tell you that when I listen to Amy Winehouse's Rehab track the words "they wanna make me go to rehab" is missing but she does sing "no, no, no". Guess a music engineer would know what part of the sound is missing but I don't. Perhaps there are two sides to music - right and left and one is missing? I do know that my netbook speakers are fine. Sometimes the headphone sound is like, well I guess, chipmunks. Kind of like a radio with interference maybe. All help appreciated. Thanks.