Audio fluctuates up and down over HDMI and analog

Question

I'm using Elementary OS (an Ubuntu spin) and the proprietary drivers for my Radeon HD 6870. It happens without warning and without touching anything, halfway through a movie the sound will suddenly become very quiet for a few minutes then loud, and keep fluctuating. This happened under Windows as well sometimes, but not nearly as often. The issue happens with multiple cables and the monitor has no problems with audio from other sources. What could be wrong?

Solution

This same thing just started happening to me. I'm using a Windows 8 HP Envy Ultrabook with an HDMI cord to an Emerson LF391EM4 LED TV, and no matter what I'm watching, after a few minutes the volume drops.

Youtube, Netflix, VLC, the volume dies out and I have to crank it all the way up.

I've solved this problem by turning off the volume leveling option on the TV. Check your menu on the monitor, check the audio settings on computer, see if there's any kind of auto-leveling function.

Comments

[fixer1234]

Welcome to Super User. Please don't post an answer to confirm that another answer worked. The site's Q&A format reserves answers for solutions to the question, and each answer should contribute another solution. The way to indicate that an answer was useful is to invest a little time in the site and you will gain sufficient privileges to upvote answers you like.

[zagrimsan]

This answer could be improved by stressing on the SRS TruVolume and StudioSound part, since the other answer was about the similar things but on the TV side. So in that sense @fixer1234 this is not stereotypical "yeah, it worked" type of a non-answer but an alternative solution.

[fixer1234]

@zagrimsan, they are about the same thing--"disabled the 'SRS TruVolume & SRS StudioSound HD' in my Vizio tv audio settings" (just referring to it with a brand name). Robert's answer mentions checking both TV and computer for any kind of volume leveling. This answer confirms fixing the problem by disabling the volume leveling in the TV.

[zagrimsan]

@fixer1234 You're correct, I missed both details, bad for me.