Can you try your audio on the page I've given below? Its a test page and will echo the audio back to you in real time.

When you click a button, e.g. Audio, do you then get the permission prompt with your microphone listed? Note that depending on your setup, there may be more than one microphone listed so you might have to select the right one.

https://mozilla.github.io/webrtc-landing/gum_test.html

Thanks for your reply.

Yes, I do get the permission prompt as usual. However no matter which input device I select (which are my microphone and stereo mix), there is no sound other than a short noise bump in the beginning sometimes (not always).

I've made a short demonstration here: https://youtu.be/rGeQDdkq-Dc

Unfortunately the problem persists with 38.0

Can you check what the sample rate of the input device is set to?

If you go into the Sound part of the control panel, select Recording, and then Properties on the default mic you'll get a properties dialog up.

On the properties dialog, go to Advanced, and check what the Default Format is.

Check that the Hz is either 48000Hz or less (the channel and bits shouldn't matter).

Please let us know if that helps or not.

It was already set to 48000 Hz, which should be the default setting, so unfortunately that didn't help.

After the problem persisted with Windows 10 and FF 40, I completely deleted the sound-drivers several times and re-installed them and it now works.

Thanks for your help!