If you are having sound problems, look here
We have not changed the sound or music code for several versions of Gal Civ. I don't know why, but people sometimes suddenly start having problems with the sound after they upgrade to a new version.
Here are some things that you can try to get your sound working again:
1) Update your sound drivers if there is a newer version. Re-install if you don't have a newer version.
2) If you don't have the latest version of DirectX installed, update it. Also run dxdiag and do all the sound tests to make sure that there are no problems.
3) http://www.stardock.com/files/ms_mp3codec.exe - this link will re-install Microsoft's default system codecs. Sometimes other programs install their own buggy versions of these codecs and overwrite them.
4) Run Windows update. I'm pretty sure that there's an update that addresses static in games.
5) http://www.radgametools.com/bnkdown.htm - this is a link to the download page for the bink tools. If another program like QuickTime has taken over your bink associations, that could cause problems with the sound. Installing the bink tools should reclaim the associations.
6) As I mentioned in #3, some programs install buggy mp3 codecs. These can also cause crashes. Windows Media Player is always safe. WinDVD and Winamp3 are known to have buggy codecs. Updating to newer versions of these programs may help if they've fixed their codecs. You probably don't need to try un-installing these programs unless you are getting frequent crashes as well as the static.
7) Make sure that the mp3s play in another media player without the static. If you're still getting static, you may need to re-install the multimedia.