I don't know what you see at the top of your group if you are on your windows computer.
BUT if you are on your Chromebook you see this little thing to click.

https://www.geocities.ws/bkbrat/ClickFirst.png

That will take you to your Site Settings.
Where you go down to Sound.

https://www.geocities.ws/bkbrat/SiteSetting.png

Sound must be set to Allow. Automatic Default is not good enough to hear sound on everything or place you click.
You choose Allow from the little drop down box.

https://www.geocities.ws/bkbrat/Allow.png