OK, I just tried to enter this command on a Mepis box I have (which is similar to Ubuntu as it is Debian based), and it appears that the dmesg command does return exactly as you have stated.
Try the following command:
You may have to type
Since you have to keep switching back and forth, if this command returns some information, look for entries that describe usb information, particularly usb controller, something that looks similar to this:
00:02.0 USB Controller: nVidia Corporation CK8S USB Controller (rev a1)
What you are looking for is whether your USB controller is recognized. If it is described in the output of lspci, then it has been recognized. Also, open a file browser (it will be somewhere under applications in Gnome), go to the /etc/dev folder and look for usb.
The output of lspci will also provide information about your sound card, but first things first. It is more important to get your usb ports working first. Soundcards are easier to configure.
Ubuntu has some of the best hardware recognition of any distro. I have not known Ubuntu not to find and configure usb controllers automatically during installation.
The Official Ubuntu forums are slower to answer but they will eventually and they are all distro specific. Also there is a search function here at LQ which has been very helpful to me in the past. This is a similar post:
Post back whatever information you can from the above commands.
Hope this helps