I haven’t used any, but if you are looking for options I’d say that you can look for a shield, but most of them use a SD card so you would have to modify the example sketches to use the SD card of the Galileo, for example I’ve seen the library of the one from Sparkfun, and uses 2 libraries for an SD card and the SPI, that’s no guarantee that it will work but it seems to have a pretty good chance. The other option are the USB audio devices, take a look at this link: http://computers.tutsplus.com/articles/using-a-usb-audio-device-with-a-raspberry-pi--mac-55876 it’s cheap enough to get one and try it, also it includes a tutorial for the Raspberry Pi with the ALSA library, but I think it’s helpful. If I’m able to get one and test it I’ll let you know.
I found an answer. Sergey has already done it:
He built a fancy USB audio device, I was not planning on doing that. But the thing that is stopping me is that any USB audio would apparently require rebuilding the a Linux image, and I have not had much luck doing that.