I found the solution to my problem. I had an old SBAudigy installed. I had done this a while back to avoid any "RealTek" problems with the motherboard onboard sound and to free up the CPU. While I have had no problems with other games (including some with voice communication) I decided to remove the circa 2004 board and let the 2013 motherboard do its thing. Everything works great now and I keep discovering new sounds in SH4 that I didn't know it had!