All of the sounds from my 2008 mac pro have stopped. The startup chime and any audio from any source can't be heard. There is no line in/out or internal speakers listed in the sound preferences anymore. I read that it might be a glitch with the digital sound inputs, so I stuck a toothpick into the audio ports for a bit and that fixed it. The internal speakers and lines in/out were showing in the sound preferences again and all sound and the startup chime worked. But then two days later the problem returned. I have tried repeatedly to repeat the toothpick fix but it no longer has any effect. Can anyone please advise on what may be wrong? Also, could I buy a usb sound card and use that for all of my audio that was previously handled by the internal speakers an the line in/out ports on the mac?