If your WebRTC audio is very faint and must be cranked all the way up to hear participants but on a Cisco Meeting App for Windows OS X or iOS the audio is fine. This is a known issue with Chrome on PCs, mostly having to do with the way it handles AGC.
A workaround is to disable the Communications option on the Windows Playback Device properties. For example, on Windows 7 right-click the speaker icon from the Task Bar and select Playback Devices. Then go to the Communications tab and set the Communications option to Do Nothing.
Windows knows Communications is active and thus reduces the volume by 80% but this is unnecessary when using Chrome. Changing this setting bring the levels up to the same as those heard in the Cisco Meeting App. (This should work without rebooting the PC, but occasionally a reboot is required for the new setting to take effect.)