2) If the answer to 1) above is YES, then you have viewer problem, as it doesn't happen that SL audio is down everywhere [Yes it could be not working in one place or another but it is not down everywhere for sure]. MAKE SURE YOU HAVE THE LATEST VERSION OF FIRESTORM.
3) Check your volume settings as shown in the picture below
I have voice turned OFF as it often annoys me and I cannot use it with family around, often.
NOTE: You probably know this already but you need to click the music icon to start music:
Make sure that you have STARTED music playback:
by clicking the music icon indicated by the red arrow.
4) If 3) did not fix the problem, there may be a problem with your FS Preferences. Here are two resources from the Wiki:
Yes you will have to read these pages as I do not know your system or what is on it. Here are screenies of my preferences which work for me:
5) If all of the above things do no work for you- have a trusted friend who knows what he / she is doing , log into your account and try to confirm or fix the problem.