Silence mode shortcut from home screen

I noticed that there is a speaker sign above the $ on the left corner of my Q10 keyboard.

Does this mean that I can use this key from the home screen to go from silence mode to non-silence mode using this key from the home screen?

If I could do this, that would be very nice.

What is the use of this speaker key on the keyboard?

Secondly, Is there any key to end the call on the keyboard itself?

Thanks!

The speaker on the $ key is to toggle speakerphone on/off when you're on a call.

Easiest way is to pull down quick settings and hit the "bell". It will toggle last used sound profile.