Ah, at least something relevant to pose a diagnosis... and mind you, the crash is not at all related with sound !
It's simply the viewer's watchdog timer kicking in (and voluntarily crashing the viewer to get out of a total freeze) when it notices the rendering stopped. The sound stuttering is simply the result of the rendering "hiccups" before the whole rendering loop freezes (sound buffering is done at each frame: when frames stop being rendered or render erratically, sound also stops, or the buffer empties and the sound streaming stalls).
Similar issues have been reported with some graphics cards/drivers combinations (apparently, NVIDIA GT (not GTX) cards seem affected) and the v3.4 renderer: it's not specific to the Cool VL Viewer and I alas cannot investigate since my own graphics card (GTX460) is not affected at all by this bug... See also the similar issues posted on this forum about freezes and timeouts, since it could also be something else (such as Windows' stupid USB plug'n play detection routines
impacting the viewer joystick detection: if this is your case, simply check the new "Never try to initialize" setting in the "joystick options", "Input controls" sub-tab, "Input & Camera" tab of the "Preferences" floater).
Your graphics card/driver could also be happier with the v2.6 renderer, in which case the Cool VL Viewer v1.26.4 will be best for you...