Is there a way to start a qube with the sound muted?

Context
This page on the Whonix documentation (and also the advanced deanonymization post) explains “advertisement tracking can link multiple devices via ultrasound covert channels”.

I believe inaudible noise can be used to associate different activities if a participating, malicious vm or external device is listening.

To reduce the risk of this happening, I want to disable the audio output on any vm that I do not plan to use with sound (e.g., vms for writing email, looking at pdfs, asking questions like this).

I can already mute the audio of a vm by:

  1. clicking the sound icon in the task bar
  2. clicking “Audio mixer…”
  3. finding the specific vm under “Playback”
  4. clicking the mute button for that vm

Question
Is there a command to do this (probably related to pulse audio but I couldn’t find it)?

Also is there a way to automatically apply this at the start of select vms (like disposables)?

Any help would be great. Thank you. :innocent:

qvm-prefs < VMName > audiovm ‘’

Or, if it suits you better, disable audio for all qubes

qvm-prefs default_audiovm ‘’

and then enable it only for specific qubes

qvm-prefs < VM_Name > audiovm dom0/sys-audio

whichever of the two you set as audiovm

This is useful because you basically don’t need audio in any template and most of qubes, except for multimedia qubes and specific browsing qubes.

Interesting approach @enmus.

I see two disadvantages though:

  1. It is static, i.e. it doesn’t work for running VMs. In particular unmuting a running VM requires a VM restart.
  2. Unmuting persists across Qubes OS reboots, i.e. forgetting to mute it again or not having a script at boot that mutes all VMs once might have security implications.

I posted a dynamic solution at [1] some time ago, but it’s not perfect either and a bit difficult to set up.
Let’s hope [1] gets implemented by the Qubes OS devs one day.

[1] Disable speaker output for domUs by default · Issue #2724 · QubesOS/qubes-issues · GitHub

1 Like

Thanks, but studies like this concerns me, though I’m far from competent to judge them, so that is why my approach is more restrictive.

As we discovered, some apps
read from the microphone at a lower data rate during
mute, but Webex reads from the mic the same way re-
gardless of mute button status.

If I want to listen to something online, most probably I’d download it and listen to it offline.
Not to say that I’m even more concerned about ultrasonic cross-device tracking