Google’s Google Plus Hangout / Gtalk plugin automatically adjust your volume to account for varying noise conditions by default. Sometimes this is an undesired behavior, but there is no button to turn it off. Here is how you do it:

Linux:

Run this in a terminal:

echo "audio-flags=1" > ~/.config/google-googletalkplugin/options

Windows:

Set the registry Key:

HKEY_CURRENT_USER\<wbr></wbr>Software\Google\Google Talk Plugin\options\audio-flags = 1

Mac OSX:

Edit the plist:

~/Library/Preferences/com.<wbr></wbr>google.GoogleTalkPluginD.plist

and set “Audio Flags” = 1

All:

When you are done, all instances of Chrome must be restarted. Simply closing the windows isn’t enough though, reboot to be sure.