Mac Forum / General / General / December 2006

I believe I had the exact same problem a while back at Youtube and was
hoping that I would find some notes on what solved the problem for me,
but alas I couldn't.

Still, from memory I think I might be able to help.

1) Specifically for the Youtube site missing audio (or any site using
Flash presentations, which the videos at Youtube actually are -Flash
files) I believe my problem was that although Quicktime indeed supports
Flash files it really doesn't do it properly, so the list of available
supported file-types in the Quicktime setup window is misleading.
I think I eventually found out that the built-in Flash support that
Quicktime has is old or buggy (in other words: useless), and I think
solved this problem by downloading and installing the latest (free)
Flash player (http://www.adobe.com/products/flashplayer/) even though I
officially was supposed to be able to read Flash files. I hope Apple
will do something about this (and yes, I have the very latest
QuickTime, and the Pro version as well).

2) If that doesn't help or you're not getting *any* audio from any
application (as I did a while back) you might want to try out this
strange trick I learnt about among many places here
(http://www.macosxhints.com/article.php?story=20060310164835119) where
it says:

------------------------------
Luckily, I found an extremely strange but workable fix in the
Macromedia forums -- but you need GarageBand in order to implement it.
Open GarageBand, and do something that generates music - I opened the
piano keyboard and played a couple notes from the Star Wars theme.
Quit.

You've most likely now got your Flash sound back.

Why this fix works, I have absolutely no idea. I imagine GarageBand
might be doing something behind the scenes, but this has to be one of
the more odd fixes I've ever run across. (But one of the most difficult
fixes to find - thus the post here.)
--------------------------------

Now, I don't have an Intel Mac (I'm using a G4 Powerbook), but that
trick also worked for me.
Hope this solves your problem too!
Please report back and tell us how it goes.