[BUG] Asus Zenbook S14 microphone not working with high-pitched sound

[mateosss]

Hello, the microphone of my asus zenbook s14 microphone suddenly stopped working during a video call on Ubuntu.

After that the microphone did not work neither in Ubuntu nor in Windows most of the time, although very occasionally it starts working again in both operating systems. I tried reinstalling Windows drivers, upgrading ubuntu kernels/sof version, and upgrading the bios to the latest version.

I am currently using Ubuntu 24.10 with kernel 6.16 with sof-bin v2025.05.

This is my alsa-info output: http://alsa-project.org/db/?f=8448f97ab288a5dba378dc14c4181d63314402f2

Yesterday I was somehow able to get the microphone working again in both OSs by running two commands recommended in this issue:

amixer -c0 cset name='Dmic0 Capture Volume' 45
amixer -c0 cset name='Dmic0 Capture Switch' on

Although today it's not working again and the commands are not fixing the issue.

The behavior of the microphone is not total silence, it produces a short high-pitched noise at the beginning of recordings and a thump-like sound whenever I modify the microphone volume or mute it with the physical keyboard key.

This is the normalized waveform of the high pitched sound:

And this is an example waveform during a recording in which I moved the mic volume slider:

Here is the three recordings coming from the following commands. output1.wav and output3.wav have the high pitched sound, output2.wav is mostly zeros.

~/D/wav (main|●1✚13) $ arecord -l
**** List of CAPTURE Hardware Devices ****
card 0: sofsoundwire [sof-soundwire], device 1: Jack In (*) []
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: sofsoundwire [sof-soundwire], device 10: DMIC Raw (*) []
  Subdevices: 0/1
  Subdevice #0: subdevice #0
~/D/wav (main|●1✚13) $ arecord -f S16_LE -r 48000 -c 2 -d 5 -t wav output1.wav
                       arecord -D hw:0,1 -f S16_LE -r 48000 -c 2 -d 5 -t wav output2.wav
                       arecord -D hw:0,10 -f S32_LE -r 48000 -c 2 -d 5 -t wav output3.wav
Recording WAVE 'output1.wav' : Signed 16 bit Little Endian, Rate 48000 Hz, Stereo
Recording WAVE 'output2.wav' : Signed 16 bit Little Endian, Rate 48000 Hz, Stereo
Recording WAVE 'output3.wav' : Signed 32 bit Little Endian, Rate 48000 Hz, Stereo

And here is the output of dmesg:

dmesg.log

I was inclined to think it might be a hardware issue since it happens in both OSs, but I am unsure since whenever it starts working again the microphone sounds completely fine.

Thank you in advance for any help!

[mateosss]

An update to this:

1. I rebooted into windows. Here I have the option to reproduce whatever my microphone listens enabled all the time for debugging. It was not working in the beginning (i.e., I only hear the thumps if I change the mic volume or mute it).
2. While using the computer it suddenly started working again after ~10 minutes.
3. I rebooted into linux and it didn't work, but this time when I ran the two amixer cset commands the microphones started working on linux as well.

This erratic behavior is pretty annoying. Not sure how much time the microphone will keep working, nor whether this is a faulty unit or a software problem.

[ujfalusi]

@mateosss, I cannot recall similar issue, usually the DMIC is either working or not, there must not be anything random regarding to it. If similar randomness present with Windows it might be electrical issue on your device, like loose connection which is affected by heat.

@lgirdwood, @singalsu do you have suggestions on what to try or what might be the reason?

[singalsu]

It's a soundwire PC but seems from topology sof-lnl-cs42l43-l0-cs35l56-l23-2ch.tplg that it's with PCH DMIC. It sounds like a hardware issue, especially that you have same issue in Windows. If a new device, take to repair/replace for warranty?

If pushing volume keys have sometimes impact, would just push of the mechanics somewhere else have impact? Could it be a poor electrical contact somewhere.

[singalsu]

The jack in hw:0,1 should be the headset microphone, is it also failing (output2.wav)?

hw:0,10 is the notebook lid stereo microphones (PCH DMIC type in this device).

[mateosss]

I see, thanks for the confirmation that it is likely a hardware issue. I will reach out to Asus' warranty.

If pushing volume keys have sometimes impact, would just push of the mechanics somewhere else have impact? Could it be a poor electrical contact somewhere.

It is not the press of physical buttons that triggers the "thump" sounds, but rather the change of volume/muting. It doesn't matter if these actions are triggered from keyboard keys or from modifying the volume slider on both windows and ubuntu. I couldn't find any other action that triggers any signal in the mic.

The jack in hw:0,1 should be the headset microphone, is it also failing (output2.wav)?

In the recording I didn't plug any headphones and the wav seems to be empty, but when I plug in headsets to the 3.5mm port, the microphone/speakers of the external device work normally.

Thanks for the help!