No sound when playing Instagram videos on your iPhone? No worries! An instant solution to this would be to check and make sure your phone is NOT on silent mode (Turn the mute from OFF to ON). Now, the only way to do this is to push up the little switch on the left side of your iPhone and make sure you don’t see the orange line. Also, make sure you turn your volume higher by pressing the + sign on the right side of your iPhone or by going to Settings -> Sounds and under Ringer and Alerts, slide the volume up.
Your screen should be like this:
PS: Before doing this, please make sure you have the latest Instagram (version 4.0) downloaded.
Hope this works for you!