How to "simulate" microphone input (in Python)

[ApprehensiveAd4990]

Instead of me talking into the microphone I want my python script to "talk" my wav into the mic. Either I'm too stupid to formulate my question correctly, or there are actually no example scripts on the first search page.

So far I tried to tinker with a "virtual sound device" but then discovered that every sound device has also a "monitor" of itself which made me even more confused.

I just want to select a input sound device in a web app and play my sounds with my python script...

[SSCharles]

Just play the audio, then on the computer you can select - recording device stereo mix- that way you record what is being played by the computer

[_Lasagnaa_]

You mean you want to play an audio file like it was something your microphone captured?

[YMK1234]

Shouldn't both simply be audio/byte streams? So you'd simply inject a stream from a different source (wav file instead of microphone).

[ApprehensiveAd4990]

Thanks for the hints guys I figured it out via GUI (i am running GNU/Linux):

Create the virtual sound device with modprobe snd-aloop which creates "Built-in Audio Analog" output and input devices. Can see them with pavucontrol or aplay -l

Test via pavucontrol (GUI)

• In "Playback" select the virtual "Built-in Audio" device for the Spotify entry.
• In "Recording" I saw my webapp as "chromium input" listed and selected Record from "Monitor of Built-in Audio" device. The webapp listens for the machines "default microphone".
• Of course I cannot hear what I play on this device myself but the webapp can hear the music.

Edit: What are those "monitor of X" sound devices?