Skype keeps microphone open after call ends

Quick update: I confirm that the behavior persists after every Skype call, even after updating Skype with the signed package from Microsoft (which should remove the package and reinstall it).

I asked the same question on Microsoft Answers, where it got a useless answer by a "Microsoft Agent" after 3 weeks and was locked shortly after, before I even noticed the answer, so I did not have the occasion to reply. 5 people clicked on "I have the same question" though.

TL;DR: sketchy microphone handling under Skype for Linux confirmed. Microsoft dodges the question.

I think it is a display bug and skype is not using the microphone afterwards.

I have run this command during skype call:

lsof | grep '/dev/snd' to see whether any microphone is used.

And found something like:

pulseaudi  1453                             vlad  mem       CHR              116,4                  555 /dev/snd/pcmC1D8p
pulseaudi  1453                             vlad   18u      CHR             116,10       0t0        565 /dev/snd/controlC1
pulseaudi  1453                             vlad   23u      CHR             116,10       0t0        565 /dev/snd/controlC1
pulseaudi  1453                             vlad   24u      CHR             116,15       0t0        591 /dev/snd/controlC0
pulseaudi  1453                             vlad   29u      CHR             116,17       0t0        671 /dev/snd/controlC2
pulseaudi  1453                             vlad   37u      CHR             116,15       0t0        591 /dev/snd/controlC0
pulseaudi  1453                             vlad   58u      CHR             116,10       0t0        565 /dev/snd/controlC1
pulseaudi  1453                             vlad   64u      CHR              116,4       0t0        555 /dev/snd/pcmC1D8p
pulseaudi  1453  1553 alsa-sink             vlad  mem       CHR              116,4                  555 /dev/snd/pcmC1D8p

It looks like my microphone is:

/dev/snd/pcmC1D8p

Then I finished the call (but kept skype opened - with the tray icon saying that skype is using the microphone) and ran the command again:

lsof | grep '/dev/snd'

This time the output contained only control entries.

pulseaudi  1453                             vlad   18u      CHR             116,10       0t0        565 /dev/snd/controlC1
pulseaudi  1453                             vlad   23u      CHR             116,10       0t0        565 /dev/snd/controlC1
pulseaudi  1453                             vlad   24u      CHR             116,15       0t0        591 /dev/snd/controlC0
pulseaudi  1453                             vlad   29u      CHR             116,17       0t0        671 /dev/snd/controlC2
pulseaudi  1453                             vlad   37u      CHR             116,15       0t0        591 /dev/snd/controlC0
pulseaudi  1453  1553 alsa-sink             vlad   18u      CHR             116,10       0t0        565 /dev/snd/controlC1

I then closed skype completely and ran that command again. The output was identical with previous:

pulseaudi  1453                             vlad   18u      CHR             116,10       0t0        565 /dev/snd/controlC1
pulseaudi  1453                             vlad   23u      CHR             116,10       0t0        565 /dev/snd/controlC1
pulseaudi  1453                             vlad   24u      CHR             116,15       0t0        591 /dev/snd/controlC0
pulseaudi  1453                             vlad   29u      CHR             116,17       0t0        671 /dev/snd/controlC2
pulseaudi  1453                             vlad   37u      CHR             116,15       0t0        591 /dev/snd/controlC0
pulseaudi  1453  1553 alsa-sink             vlad   18u      CHR             116,10       0t0        565 /dev/snd/controlC1