Virtual reality means artificial reality which can be realized through five senses. Observation can be possible as virtual reality leads to that human being are at tele-existence. In addition, human beings can have teleconferences and do cooperative work in the virtual reality environment. If we hear 3D sound in the space of virtual reality, we can almost realize such operations. 3D sound is essential to realize virtual reality. A variety of factors need to be considered such as intensity of sound delivered to ears, frequency spectrum, phase of sound and auditorial senses to implement 3D sound. In this paper, the information of the software can be transferred to the hardware, the hardware can be controlled, then 3D sound for teleconferences can be implemented in the virtual space, using Head Related Transfer Function (HRTF). Furthermore, it can also apply to 3D games.