The Pi has an audio output however nothing happens when you plug an audio jack in.
A little Linux is required:
lsmod | grep snd_bcm2835
amixer cset numid=3 1
(To return to the default settings change the final '1' to '2'.)
I can now use the Pi as a media player, whilst simultaneously using my BBC computer as a productivity machine. My music media files are stored on an external hard drive on my home network. Altogether I am a happy nerd.
I cannot, however, force the audio through the headphones audio jack when using RISCOS on the Raspberry Pi. I have tried changing the config.txt file by following online instructions but so far have had no luck. If anyone knows how to do this then please get in touch.