Don't panic. You need to find the directory with the plugins - i.e. for Firefox. It's a directory where you find the main libflashplayer.so file with the plugin. To fix your audio, you also need a similar but much shorter file, libflashsupport.so, to be found in the same directory. Well, you will have to compile it yourself.
Go to the page of flashsupport. At the bottom, you will find the flashsupport.c source. Save it on your disk in the directory with libflashplayer.so and compile it. In the ideal case, the following three commands are enough (please join the first three lines into a single command with many arguments):
cc -shared -O2 -Wall -Werror -licuuc -lssl flashsupport.c -o libflashsupport.so ldd libflashsupport.so sudo cp libflashsupport.so /usr/lib
cc -shared -O2 -Wall -Werror flashsupport.c -o libflashsupport.so
Then you follow the other two commands above, or copy the resulting libflashsupport.c file wherever you need, to the directory with the other "so" plugins. In my case, the audio in Flash started to work after I restarted Firefox. I hope that you will be equally lucky. ;-)