My sound goes off from alone

[Magdaachan]

Everytime when I am watching a video or hear music, the sound of my phone goes off by itself.
One time I watched a video, with half of the volume, and then it randomly got quiet. I was confused, but the video didn't stop only the sound was off. It is really annoying, does anybody know how to make it normal again?

 

[B. Diddy]

Welcome to Android Central! Which phone, and which apps does this happen on? Is it only for locally stored media, or also streaming media?

 

[Magdaachan]

It happens everywhere were you can hear music.
It happens mostly on You tube or something with the internet

 

[B. Diddy]

Does it also happen in Safe Mode? https://support.t-mobile.com/docs/DOC-30620

 

[Magdaachan]

It really helped, thank you.
Now I now what I should do if something with my phone happens!

 

[B. Diddy]

Great! If the problem comes back in normal mode, then you may have to uninstall apps one by one until the problem goes away.