Ubuntu – Strange noise in headphones when no sound is played


There is a strange noise from my headphones on Lenovo T440. The sound is like when you tune your radio, but you get a wrong frequency and you hear unpleasant noise. The noise starts when Ubuntu 14.04 boots up and ends after a shutdown. It is coming out only through my headphones, there is no noise through the speakers.

The strange thing is that the noise disappears when any sound is played or if I enter sound preferences. But when a sound is stopped, it appears again after 10 seconds or less. Also, the noise goes way down (or maybe even disappears) if I put in my laptop charger and stop the music.

No matter how I change my volume level, the noise level is the same. It seems like the output is not disabled after sound stops.

sudo aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: HDMI [HDA Intel HDMI], device 3: HDMI 0 [HDMI 0]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 0: HDMI [HDA Intel HDMI], device 7: HDMI 1 [HDMI 1]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 0: HDMI [HDA Intel HDMI], device 8: HDMI 2 [HDMI 2]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: PCH [HDA Intel PCH], device 0: ALC292 Analog [ALC292 Analog]
Subdevices: 1/1
Subdevice #0: subdevice #0

Best Answer

Got the same problem on Dell XPS15 (9550, 2015 model in Xenial). Solved it in alsamixer and muting the loopback channel.

$ alsamixer

Navigating to loopback (all the way to the right, with key) and setting it to Disabled using the key.

  • No reboot needed;
  • No root needed;
  • Is permanent as far as I noticed.
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