Why does my volume fades out on my galaxy s7 edge when watching videos?

[AC Question]

When ever I'm watching a video the volume will fade out and I can't hear anything. Even when I'm texting this my key sound fades out. How can I fix this?

 

[jjdelarosa10]

Same here. The only way to get all sound is to wear headphones. But what good is a phone with no speaker working