Why did the sound is only on using headphones when playing mkv files

[AC Question]

My phone was able to play mkv files, now I'm able to hear the voice when using headphones only, otherwise the sound is just a buzz

 

[AC Question]

How to resume the sound

My phone used to play all mkv files but suddenly they work only on the headphones. This started 2 days ago. If I'm not using the headphones it is just as if I'm playing high speed or forward voice

 

[belodion]

[Two threads merged.]