Many people have complained of a wierd wave hiss in there headphones. Nealy all ubuntu distros I have tried this sound will play everytime there even if there is no audio playing.
My Fix:
echo 0 | sudo tee /sys/module/snd_hda_intel/parameters/power_save_controller
echo 0 | sudo tee /sys/module/snd_hda_intel/parameters/power_save
Some reason this works 🙂 I just found it on some forum somewere
hope this fixed it…