OfficeSuite HD Meeting - Mute Audio When Joining A Meeting
Meeting attendees can choose to turn their microphone on or off when joining a meeting through the Audio Settings page. This turns off the microphone every time an attendee joins a meeting. To turn the microphone off on an individual meeting basis the attendee can disable audio on the Join a Meeting pop up screen.
Through the Audio Setting page
Click the gear underneath the avatar in the top right corner to open the Settings menu. Click on the Audio menu option. Scroll down toward the bottom of the page. Check Always Mute Microphone when Joining Meetings to enable. A white checkmark will appear in the checkbox. Now when you join into meetings your PC audio will always be muted. If you click the checkbox again you will disable the feature allowing you to join meetings with your PC audio unmuted.
When Joining a Meeting
You can also disable audio before joining a meeting by toggling the Do Not Connect to Audio option after clicking "Join a Meeting:"