Default [Q] Can't hear audio alerts on android browsers ( desktop mode ).

I have registered for a live chat service for my website. When I am on my desktop , whenever a visitor pings me, I get an audio alert but when I use the default browser on my note in desktop mode, the chat does work but there is no audio alert. Please tell me if it is even suppose to work. I need this audio alert feature as I can't be on my desktop all the time.

And I use the default browser because chrome firefox and other switch to chat console's mobile mode automatically which does not have a sound alert option.