I will say that I have written, and erased this response many times before actually posting. Admittedly, this is becoming frustrating. Somehow the fact of TC being just a toolkit holds heavy relevance, and when I ask for clarification on specific terminology and how it relates to resolving this issue, I get the response that TC is a toolkit, and I am immediately directed to some additional resource, and that I don't know enough about Linux to use TC, because it's just a toolkit.
Let me explain my application of TC once more. My company has at least 50 thinclient terminals that are still in good working condition that we've had for years. We bought them when thin clients were way less expensive than they are now. We would like to continue using them to connect to newer server technologies -- namely Windows Server 2008r2 and 2012. Toolkit or not, TC loads right up on the thinclients, and works great. The socat extension will allow us to continue using the thinclients as print servers also. The rdesktop extension (an additional tool to add to the kit) plays well with the new server base, which was the biggest bridge to cross. However, it's not perfect, sound being one of it's very few flaws -- at least in this case.
Toolkit or not, I really don't think I need to explain the value of getting this issue resolved. Fifty refreshed thinclients, or 50 new PC's? It is more than a toolkit for us, but you can call it what you want.
Back on topic, this same sound issue with rdesktop was addressed on another thread that is still unsolved. Perhaps I should have gave up then.