The GVU Virtual Environments Group developed a virtual world for treating Vietnam veterans suffering from post traumatic stress disorder.  AudioLab was used to design and edit the soundscape for this environment.  Virtual Vietnam utilizes Hollywood audio production libraries to create a high intensity soundscape highlighted by powerful bass explosions and three dimensional gunfire effects.  While riding in the Huey helicopter, the user is seated in a special chair with a 100 watt subwoofer speaker incorporated into its base.