Can't seem to make USB microphone the preferred input

[Nick Moffitt]

My laptop has a built-in audio port that accepts a three-channel ⅛” plug for a stereo+microphone headset. Unfortunately due to the nature of the beast, there is rather a lot of cross-talk, and the electronics in the laptop are not the best. Also the DSP inside the laptop is surrounded by sources of magnetic interference such as the fans, power supply, WiFi antenna, etc.

When I plug in my nice USB microphone, I always have to go into the sound settings tool and hunt over to the input tab and select it from the listing in order to get audio through it. It's lucky that I know how to do this, as some folks would simply plug it in, test it, and decide that it doesn't work!

While I would argue that USB audio devices should be preferred over built-in laptop chips, I am most frustrated by the lack of ability for me to even say "From now on prefer this specific audio device for input, whenever it is present".

I want to make my USB microphone Just Work without all the clicking about!

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: gnome-control-center (not installed)
ProcVersionSignature: Ubuntu 3.19.0-28.30-generic 3.19.8-ckt5
Uname: Linux 3.19.0-28-generic x86_64
ApportVersion: 2.17.2-0ubuntu1.4
Architecture: amd64
CurrentDesktop: Unity
Date: Tue Sep 15 09:09:22 2015
InstallationDate: Installed on 2014-05-29 (473 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417)
SourcePackage: gnome-control-center
UpgradeStatus: Upgraded to vivid on 2015-05-05 (132 days ago)

[Nick Moffitt (nick-moffitt)]

The command-line way to do this seems to be:

$ pacmd load-module module-switch-on-connect

Which works fine. I am willing to be convinced that this is a bad default for some reason (and I'm going to file that as a separate bug) but at least the control centre should give me a checkbox to flip this on!

[Nobuto Murata (nobuto)]

I had a similar frustration when I used a USB headset. I put the content below as a workaround.

[~/.config/pulse/default.pa]
#!/usr/bin/pulseaudio -nF

.include /etc/pulse/default.pa

## Whenever a new sink or source appears, this module will switch the
## default sink/source to be the new sink/source
load-module module-switch-on-connect