OpenMW crashes in exterior cells if no sound device installed

OpenMW crashes shortly after entering or loading into an exterior cell if no sound device is installed or detected. Seems fully playable in interior cells, but crashes a few seconds after entering an exterior cell. All sounds seem to also have 0 duration; NPCs do not lypsinc during greetings or other dialogue with audio and during chargen, the name textbox appears immediately and does not wait for Jiub to finish speaking.

Tested on a laptop with malfunctioned onboard speakers; Windows does not recognize that a sound device is installed in device manager. OpenMW plays normally with a USB sound adapter, whether or not it's connected to a speaker or headphones.