How to set google now to use the media volume instead of system volume? For a long time I thought something is wrong with Google now that it doesn't say anything when I ask it questions.

Now I've finally found out the reason - it uses the system volume instead of the media volume (the one that is usually used in games). Since I've set the system volume to be mute and I sometimes set the ringtones to be quite, it makes Google now itself to be quite.

My question:
Why does it use it? what is the system volume used for?

According to what i've found , system sound is used for key typing ,lock screen sounds, and camera shutter sound

Can I set google now to use the media volume instead?
Not sure from which version of Android it has changed, but on my Pixel 2 with Android P, it uses media volume.

So it doesn't matter anymore.