頭相關轉換函數的量測和重建三度空間聲音的模擬

Abstract

本研究旨在建立三度空間量測系統與量測具有迴響特性之頭相關轉換函數(Head-Related Transfer Function)。除此之外，我們亦探討下列主題：(一)研究三度空間聲音之物理特性與人類對三度空間聲音定位之感知。(二) 在實驗室內論證三度空間聲音定位理論之可行性與實際上量測設備建立所引進來的雜訊失真對頭相關轉換函數的影響。(三)以水平面(Horizontal Plane)、中間平面(Median Plane)、前平面(Frontal Plane)來分析所量測到的頭相關轉換函數。(四)提出一快速演算法－“預先運算HRTF通道差值法”來減少即時三度空間聲音定位實現之運算量。(五)研究具有迴響特性之頭相關轉換函數來實現三度空間聲音之可行性。 本論文研究結果如下：(一)我們成功的利用我們(自行設計)的量測系統測量具有迴響特性的頭相關轉換函數。使用自行設計之量測系統之優點是能夠設計實驗參數、收集想要之量測數據及分析資料。(二)我們成功的利用預先運算HRTF通道差值法，使得即時的三度空間聲音重建之運算量減少1/2並以一般運算方法與我們所提之預先運算HRTF通道差值法來實現三度空間聲音。經9位受測者試聽後，可以得知其後者之平均分數較高

In this research, we construct a measurement system for measuring 3-D Head-Related Transfer Functions (HRTF) with reverberant. We also explore the following subjects: (1) studying the characteristics of 3D sound and the human perception to 3D sound localization, (2) evaluating the 3D sound theory in laboratory and estimating the noise/distortion induced by measurement equipments, (3) analyzing the Head-Related Transfer Function measured by our measurement system with focuses on the Horizontal Plane, the Median Plane, and the Frontal Plane, (4) proposing a fast algorithm, Pre-calculated HRTF Channel Difference Method, for reconstructing 3D sound in real time, and (5) studying the possibility of reconstructing 3D sound using Head-Related Transformation Function with reverberant. We have obtained the following results. (1) We successfully use our (designed) measurement system to measure Head-Related Transfer Functions with reverberant. One advantage of using our own system is that we can design the experiments, collect the desired data and perform through analysis on our data. (2) We successfully reduce the operations needed for 3D sound reconstruction by a factor of two by using the proposed Pre-calculated HRTF Channel Difference Method. We have a 9-person panel to hear and judge the reconstructed 3D sound quality using the traditional method and our proposed method, and the average score of our proposed method is higher.