I have exactly the same problem, whenever someone talks on for example on Teamspeak 3 (or any other application plays a sound), the volume gets lowered.
I already set the option under the sound settings for communication to "do nothing", but thats exactly what it does... nothing. It keeps lowering the volume.
I also tried to uncheck the "exklusive Control" checkboxes, both for mic and Speakers, but that also didn't help.
Here is the dump from meters.exe: I was running teamspeak and diablo at the time, for testing, but at that time no one talked. I did a dump like 2 seconds after the volume was lowered in the game, alt tabbing out of it. But the info was exactly the same.
Hope you can do something with this, as this is really annyoing as hell.
Microsoft Windows [Version 10.0.10240]
(c) 2015 Microsoft Corporation. Alle Rechte vorbehalten.
-- Playback devices --
Lautsprecher (Realtek High Definition Audio)
Peak: 9.32863e-008
Mute: 0
Volume range: 0% to 100% (-65.25 dB to 0 dB in steps of 0.03125 dB)
Master: 40.0699% (-13.5938 dB)
Channel 1 of 2: 40.0699% (-13.5938 dB)
Channel 2 of 2: 40.0699% (-13.5938 dB)
Active session #1
Peak value: 1.00001e-009
Icon path:
Display name:
Grouping parameter: {37ff4fbc-c130-4e6a-adc2-6cccd9092c26}
Process ID: 8288 (single-process)
Session identifier: {0.0.0.00000000}.{b241d348-3b49-43c0-9c23-f224aecc8621}|\Device\HarddiskVolume8\Spiele\Diablo III\Diablo III.exe%b{00000000-0000-0000-0000-000000000000}
Session instance identifier: {0.0.0.00000000}.{b241d348-3b49-43c0-9c23-f224aecc8621}|\Device\HarddiskVolume8\Spiele\Diablo III\Diablo III.exe%b{00000000-0000-0000-0000-000000000000}|1%b8288
System sounds session: no
HWND: 0x572F04CE Diablo III
Master volume: 1 (0 dB FS)
Not muted
Channel #1 volume: 1 (0 dB FS)
Channel #2 volume: 1 (0 dB FS)
Active session #2
Peak value: 1e-009
Icon path:
Display name:
Grouping parameter: {fa28c700-b48f-4e23-a7c8-c821aed93667}
Process ID: 3708 (single-process)
Session identifier: {0.0.0.00000000}.{b241d348-3b49-43c0-9c23-f224aecc8621}|\Device\HarddiskVolume7\Tools\TeamSpeak 3 Client_64bit\ts3client_win64.exe%b{00000000-0000-0000-0000-000000000000}
Session instance identifier: {0.0.0.00000000}.{b241d348-3b49-43c0-9c23-f224aecc8621}|\Device\HarddiskVolume7\Tools\TeamSpeak 3 Client_64bit\ts3client_win64.exe%b{00000000-0000-0000-0000-000000000000}|1%b3708
System sounds session: no
HWND: 0x000B0314 TeamSpeak 3
Master volume: 1 (0 dB FS)
Not muted
Channel #1 volume: 1 (0 dB FS)
Channel #2 volume: 1 (0 dB FS)
Realtek Digital Output (Realtek High Definition Audio)
Peak: 0
Mute: 0
Volume range: 0% to 100% (-96 dB to 0 dB in steps of 1.5 dB)
Master: 50% (-10.5086 dB)
Channel 1 of 2: 50% (-10.5086 dB)
Channel 2 of 2: 50% (-10.5086 dB)
-- Recording devices --
Mikrofon (Realtek High Definition Audio)
Peak: 0.00790405
Mute: 0
Volume range: 0% to 100% (-17.25 dB to 30 dB in steps of 0.03125 dB)
Master: 100% (30 dB)
Channel 1 of 2: 100% (30 dB)
Channel 2 of 2: 100% (30 dB)
Active session #1
Peak value: 0.00762241
Icon path:
Display name:
Grouping parameter: {4acffcb5-300a-4c51-9572-615655c8dc15}
Process ID: 3708 (single-process)
Session identifier: {0.0.1.00000000}.{ba98925a-d3a9-41d9-a593-32599a492aa0}|\Device\HarddiskVolume7\Tools\TeamSpeak 3 Client_64bit\ts3client_win64.exe%b{00000000-0000-0000-0000-000000000000}
Session instance identifier: {0.0.1.00000000}.{ba98925a-d3a9-41d9-a593-32599a492aa0}|\Device\HarddiskVolume7\Tools\TeamSpeak 3 Client_64bit\ts3client_win64.exe%b{00000000-0000-0000-0000-000000000000}|1%b3708
System sounds session: no
HWND: 0x000B0314 TeamSpeak 3
Master volume: 1 (0 dB FS)
Not muted
Channel #1 volume: 1 (0 dB FS)
Channel #2 volume: 1 (0 dB FS)
Edit:
I think i have it.
I had Soundblaster Cinema application installed, wich worked perfectly on Win 8.1 before, but it doesn't work on Win 10 (and still no Win 10 Verstion from Creative or MSI available...),it always crashes as soon as it is clicked in the systray.
So i removed it from the autostart, having believed to have gone around the problem this way.
But that was not the case.
Now i completely uninstalled the Software and that seems to have fixed the Problem.
I will do some testing now.
I will edit my post if my first observation is not right and it still isn't gone.