使用3D音效系統以增強虛擬實境體驗之研究

Study of Using a 3D sound system to enhance the virtual reality experience

虛擬實境（Virtual Reality, VR）體驗主要是透過對人體五種感官的刺激，讓使用者全心投入於虛擬的世界當中，進而讓使用者認為這個虛擬的世界是真實的。從1968年Ivan Edward Sutherland創造出史上第一台頭戴式顯示器開始，虛擬實境的技術皆是以頭戴式顯示器的樣貌出現，而虛擬實境的發展之所以會圍繞在頭戴式顯示器的開發，其原因是因為視覺的感官刺激佔據人類感知的比例達87％。虛擬實境的體驗和電視電影的體驗相同的是，透過視覺給予使用者精彩的內容，並藉由聽覺給予使用者生動的效果，讓使用者擁有良好的視聽體驗，但不同的是由於在虛擬實境的體驗過程中，使用者會因為不斷的轉動身體而沒有固定的體驗方向，因此和電視電影的視聽體驗有很大的不同，此情形將導致喇叭位置固定的揚聲系統不適用於虛擬實境，所以虛擬實境的聲音播放系統往往是透過雙聲道耳機作為標準配置。在配置耳機的虛擬實境體驗當中，為了讓使用者在虛擬的世界當中，模擬人在真實世界聽到的聲音，因此需要高度的三維立體聲技術作為聲音設計的基礎。有鑑於上述，本研究透過Ambisonic的3D聲音系統作為聲音設計的基礎，並建立一個虛擬實境的聽覺實驗，透過實驗評估使用者在虛擬實境體驗中對於聲音定位的準確度，並聚焦於驗證聲音對於虛擬實境體驗的重要性，以及探討只有聽覺的虛擬實境是否可以作為一種虛擬實境體驗的方式，並提出以聲音為主之虛擬實境體驗的設計建議。 By the stimulation of the five senses of a human body, virtual reality (VR) allows users to become fully engaged in the virtual world, and thereby makes them believe that the virtual world is real. Since Ivan Edward Sutherland created the first head-mounted display in 1968, various VR technologies have been introduced with head-mounted displays. Concurrently, the development of VR relies on that of the head-mounted displays because visual sensory stimulation accounts for up to 87% of human perception. VR experiences are similar to television and movie experiences in some aspects. Both of them provide users with remarkable content visually and make the content intense by auditory stimulation. This allows the users to have phenomenal audio–visual experiences. However, during VR experiences, users turn their bodies constantly, and so, there are no fixed directions for their experiences. Thus, VR experiences differ significantly from their television and movie counterparts. This makes loudspeaker systems with fixed positioning unsuitable for VR. Hence, two-channel headphones are generally used for VR audio playing. In VR experiences using headphones for the users to become fully engaged in the virtual world, sounds that people hear in the real world need to be simulated. Therefore, three-dimensional stereophonic sound technologies have to be employed as the basis for the sound design. Thus, this research adopts a three-dimensional sound system based on Ambisonics for sound design and constructs a VR auditory experiment. By the experiment, the accuracy with which the users can locate sounds during VR experiences is assessed. The importance of sounds in VR experiences is also verified. Furthermore, consideration of VR experiences with only auditory stimulation as a type of VR experiences is discussed. Design recommendations are made for VR experiences mainly based on sounds.