LL released some new development code, and an experimental SLVoice binary with it. This should be usable with the standard viewers from LL, Windlight, as well as ones built from source. Here’s how.
First, download the libraries package. This file contains libraries and headers needed for building a viewer, as well the SLVoice binary.
Uncompress the file.
In linden/indra/newview/vivox-runtime/i686-linux/ you’ll find all the voice files.
If you run the standard viewer downloaded from secondlife.com:
Copy SLVoice into the installation directory
Copy the rest into the lib directory
If you build your own viewer and run it from the source tree:
Copy SLVoice into indra/newview
Copy the rest into libraries/i686-linux/lib_release_client
Now if you start the viewer, voice should work. This is of course experimental, and might crash, but it seems to work a lot better than the Wine hack did.