Input feedback sounds play via left channel only

[Luke Horwell]

In Ubuntu 14.04 LTS (and possibly 13.10), input feedback sounds (played when a button is pressed for instance) play only from the left channel through both speakers. This version of pulseaudio is 4.0.

It is expected that the sound plays closer to the edge of the screen where the cursor is. However, in this case, sound is quiet or heard at all when a button or alert dialog appears closer to right edge.

This can be easily re-produced by performing the following steps on a live session of Ubuntu 14.04:

1) Type "dconf write /org/gnome/desktop/sound/input-feedback-sounds true" into the terminal to enable input feedback sounds.

2) Open gedit, go to Help → About, and click on the "Close" button. If the window is positioned closer to the left, it's heard clearly through both speakers, however when nearest the right, it cannot be heard at all, due to the fact it's outputting the left channel only.

I've attached some logs of pulseaudio which may help identify the issue.

Gathered by performing the following:
1) Edit /etc/pulse/client.conf and edit " ; autospawn = yes " to "autospawn = no"
2) Kill the demon " pulseaudio --kill "
3) Start the demon again and redirect log output to the live session's desktop
    " pulseaudio --log-level=4 -v --log-target=file:/home/ubuntu/Desktop/pulseaudio.log "

For comparison, this bug does not appear to be present in Zorin OS (based on Ubuntu 14.04) by performing similar steps, with Zorin's logs are attached for comparison. Simplified logs of both OS' pulseaudio output are attached from another earlier output, which when compared for differences, shows Ubuntu tries to force a resampler 'copy'.