HTC One speaker problem - One speaker turning off / mono sound

[Apex43]

My HTC has started to go either mono or one speaker turns off for 5 seconds then the problem occurs about 30 mins later when I watch long movies. I know it's not the movies so it must be the phone. Anyone have a solution or have the same problem?

 

[Lefank]

My top speaker does that to when listening to music

 

[t ONE]

Happens so much to my phone when listening to music, dont watch movies on my device so cannot say anything about that, but streaming music or playing that on my phone, it play normally for a while, then FLIPS OUT like goes mono as you said and then back to normal! I thought the problem only persisted on the speakers, but when I attached the earphones, the same thing happened, however, after I installed 4.2.2, what version do you have? I might think that this is a software issue, BUT I really don't know because I updated my phone's firmware the week I got it. Was and am a little occupied at the moment, but will surely contact HTC and find out more and update my post!