In my Dell Inspiron 5500 notebook, I've got a SigmaTel C-Major integrated sound card. Linux detects it and uses an AC97 audio codec.

The problem is the XP drivers for it arent too good. When I got my earphones on, I can hear this small hissing when nothing is playing. It was even more but I muted the cd-audio and it dropped to a smaller hiss. When I play an mp3 and there is silence in the music, I can hear a very high pitched tone.

It doesnt seem to be a problem with the sound card since under Linux, it is perfectly silent when nothing is playing. No noise. Nothing. So I suspect its just a poorly written XP driver.

Anyone notice this problem and any solutions to fix it? Many thanks.

Interesting...

You got the driver to work with linux but not with XP? My roommate has a Dell Laptop and for him, it's the exact opposite. The driver that came with the laptop works fine on XP (except for a little problem - you have to Run->Sndvol32.exe everytime you want to bring up the volume controls). On Red Hat 8, however, it plays audio files too fast. This can be noticed when attempting to play video. The audio skips while it tries to slow down to keep sync with the video.

Ok, if anyone is still awake after reading this, comments/suggestions/queries/money will be most welcome.

Hahaha, the funny thing is that I just sold my Latitude D600 to a friend today, which also had the SigmaTel sound (along with the noise). My new IBM T41 has SoundMax, which has no noise. No idea about how to fix your problem with the Dell, though. I never tried Linux on my old one since the TrueMobile 1400 wireless card doesn't work in Linux.

Just an idea...

Did you mute the line-in under the sound control panel when listening under windows?

Install Alsa drivers instead of oss ones. Alsa will correctly resample the audio to the 48khz needed by the sound chip.

http://www.alsa-project.org

Yeah, this isn't the problem - it's still there when everything but WAVE is muted.

Just an update on this hissing problem. I fixed it. Looking at the startup messages in Linux (dmesg), I noticed it detected my soundcard as an Intel AC'97 so I went into XP, uninstalled the stupid SigmaTel ones, then put on the Intel AC'97 drivers (that came with XP) and it works! No apparent hissing, no apparent quality degradation, etc.

I'm very happy now.

I don't know what kind of time machine you've got, but last time I checked it was only up to 5150

No more noise, but also no more of SigmaTel's power saving thing, hehehe :B

haha That was a typo. I meant 5100.

Yeah well, can't have everything perfect though I prefer having clean sound than having an extra few minutes of battery life.