Once you enable audio on Instagram, sound now continues until you close the app
So you might ask yourself, what is the advantage of this feature? Well, it means that Instagram users won't have to turn the audio on for each individual video, which could be a pain in the you know what. As far as Instagram Stories are concerned, the audio will match the settings on your phone. Which means that as long as your handset is not on mute, Stories will play with the audio on.
The bottom line is the bottom line, which will fatten up with more advertisers. Why? Because now advertisers will see more of their videos play with audio enabled. This will make them more likely to fork over the money to advertise on the app. After all, an add with no volume is most likely to be ineffective.
Of course, most Instagram users would rather not get startled or embarrassed by audio that they weren't expecting to hear, playing loudly in their ears. On the other hand, with video becoming a larger part of the Instagram experience, keeping the app mute would make it a silent movie in the era of talkies.