Sound goes away

After few minutes the sound is gone in chess.com.
is this a bug? Or what could be wrong? Another problem is wavering light. Since few days I had such problems.

But ONLY during playing chess.

I'v got the same problem here. After a couple of games there is no sound anymore. I'v checked it and it's only with chess.com

Could this be fixed? Thank you!

It happens to me often, I just reset my browser, and it fixes it.  Even during a game(if it's a longer game) I'll just reset my browser.  Probably a good idea to reset your browser before you play a game(s) anyways.

Yep, I'm still having this problem too.  Nothing I've tried has worked.  I reboot and it works fine.  I hear sound (a thud noise when a move is made) until about halfway through the game or so, and it suddenly stops working. 

Additional games after that are all without sound, from Move #1. 

If I take the time to restart the broswer or reboot... everything is fine again... until about halfway through the game. 

Now and then I can actually get a FULL game in without a problem!

Never had this issue before... been playing here for years.

I'm using the latest version of Firefox and Windows 7.

Would bet you are all using Windows 7 and Firefox.  As of the last Firefox update to v34, there is a problem with it and the audio service in Windows. You can close and restart your browser, or the Windows audio service to fix it. 

Best to just use another browser to play chess