Call Hold and Multiple Call Features
You can put your calls on hold when you’re using the Call Phone feature in Gmail or computer to computer voice and video chat. Call hold lets you freeze your video feed or your voice feed so that the person you’re talking to can’t hear or see you. When you place a call on hold you’ll also be unable to hear or see the person you’re speaking with.
To put a call on hold simply press the button in the Chat mole. To take a call off of hold just press the Resume button.
You can make or receive multiple voice calls or computer to computer voice and video chats by starting a new call, voice, or video chat in a new Chat mole. This will put your current call on hold.
While you can have as many voice calls or computer to computer video chats at the same time as you'd like, only one call can be active at a time (all other calls will automatically be placed on hold). You can switch between multiple calls by pressing the Resume button in the Chat mole of the call you wish to make active, at which point all other calls will remain on hold.
Caroline is a Hangouts expert and author of this help page. Leave her feedback below about the page.