Other users have reported screeching sounds when using volumio with this device, it may be of interest that the same problem occurs with XBMC on the pi, however XBMC on Ubuntu does not have this problem, if any one can tell me what differences in the configuration files could cause this I would be grateful to know, if it requires debugging then I can send someone the relevant files. If you need help debugging please can someone stop volumio requiring a complete re installation on attempting to change a buffer size parameter.
This may be a possible solution for someone who is skilled in the art of software engineering. There is a fix for Ubuntu, although I must say I never saw the issue in all the time I used Ubuntu but some people did and this fix apparently worked.