Ubuntu – Buzzing from the speakers when idle Lenovo Y410P

I have a buzzing constantly from my speakers when no sound is being played.

If I open sound settings, the speakers POP and then they are silent. (I don't even have to mess with any of the settings.) Once I exit, the speakers POP again and then the buzzing comes back. If I have anything that plays sound on, the buzzing goes away.

I know others have tried turning off automute. I have tried turning off automute in alsamixer but the buzzing does not go away.

I am using a lenovo y410p. Two sound cards show up in alsa mixer: HDA Intel MID and HDA Intel PCH:

EDIT:

I should also note that in alsamixer, for sound card 0[MID] I do not have any options for volume control. I only have these in alsamixer for sound card 1[PCH].

Audio Devices:

cat /proc/asound/cards
0 [MID ]: HDA-Intel – HDA Intel MID
HDA Intel MID at 0xc2610000 irq 49
1 [PCH ]: HDA-Intel – HDA Intel PCH
HDA Intel PCH at 0xc2614000 irq 50

Sound card information from the terminal can be found here: my google doc

New discovery:

When my computer is plugged in and I adjust any setting of the volume (mute, unmute, volume up, volume down), the buzzing goes away. As soon as I unplug my computer, the speakers POP and the buzzing comes back.

When I plug the computer in, with the speakers buzzing, the buzzing continues until I adjust any setting of the volume (mute, unmute, volume up, volume down). Then the buzzing goes away.

This suggests to me that "auto-mute disabled" is being overridden on battery power. It seems like auto-mute is activating on battery power regardless of whether or not I have auto-mute disabled. Am I off-base for thinking this?

I don't think this is an electrical issue, since I am dual booting windows and have no such problem with windows.

EDIT: Sunday March 16, 2014

Thanks to onecoder4u for pointing out that the buzzing only happens when the keyboard back-lighting is on dim, but not when keyboard back-lighting is off or on high.

Ok, I can live with not having my keyboard on dim. This solves the buzzing but not the popping issue. I still get a loud pop from my speakers whenever the computer switches between playing sound and not playing sound. I have no issues at all when my computer is plugged in.

I would mark this question as answered, but I am still having part of the problem.