The UniAud sound drivers have been refreshed (9/23/2013). This is based on the GPL ALSA Project from Linux and provides drivers for various sound chipsets, including HDA, AC97, and PCI cards. There are some known problems with the 2.x series, such as "pops" at the end of WAV files. Note that the cause of repeating system sounds has been found to be a bug in IBM's SND.DLL, and there is a workaround available. For what it's worth, this project has stagnated for quite a while now; the stable code is based on ALSA 1.0.21 from mid-2009, the test releases are based on ALSA 1.0.24 from early 2011, and the current upstream version is 1.0.27.
Source: OS/2 Warp News and Rumors