Ouch - we only have one system that can/could repro this and it worked fine after the "fix".
The fix was also a workaround to a OpenAL bug rather than our code, but I'll see what our next options are.
Will continue to test using different sound cards/ sound sub-systems/ drivers, but would much prefer to use my high-end ASUS discrete PCIe sound card in any event.
BTW, Upon reflection, this problem manifested itself with earlier builds of TRS19 (but not the first, as I recall) then disappeared for quite a while (e.g. Builds 98149, 98299, 98592) until about Build 100240, when it reasserted itself.
Question: What is different in the OpenAL code for T:ANE SP4 RC and this current TRS19 build? Same session scenario/ assets, etc. in T:ANE do NOT have this CTD problem.
Edit update following further tests: Crash to desktop still occurs when 3D sound is turned 'Off' and sound volume is set to any level other than 'Off'.
Changing the sound card and drivers to either the (mobo built-in) Realtek or nVidia High Definition Audio resulted in zero CTDs under the same known trigger conditions (but execrable sound quality via the monitors' built-in speaker output!)
Interestingly, when moving it back to the ASUS Xonar HDAV 7.1 surround-sound system and fiddling again with the audio stream sample rate frequency, this also resulted in zero CTDs!
Will continue to test...