6 weeks later....

Are you talking about in the mydlink app or mydlink lite app or mydlink.com?
All interfaces will have a microphone/speaker icon on the live view page. click/tap it to turn it off.
On the mydlink app, on the live view screen, tap the square icon in the bottom middle. Tap the speaker icon and select the one on the right wih the X on it.
I cannot double check the mydlink Lite or mydlink.com since I updated the firmware on mine to 2.00.