I can't hear any sounds when I browse java applets in Netscape 4.61. I know the sound is set up correctly on my Red Hat 6.0 system as I can run RealPlayer with no problem.
Java in Netscape 4.61 under Linux does not support sound, and I don't believe Netscape (AOL) has any short-term plans to change this.
it may be possible to incorporate an add-on library to fix this. I am looking into the problem further.
Correction: http://www.alumni.caltech.edu/~dairiki/libmmoss/this library can perhaps help you with your problem: http://apps.freshmeat.net/download/907734069/