以平面喇叭陣列為基礎之個人3D虛擬劇場

Abstract

本文提出以平面喇叭陣列為基礎之個人3D虛擬劇場。本系統平台建立在個人多媒體電腦上，它可以虛擬出空間任一方位的音像並且與影像同步播放。使用到的技術包含頭部轉移函數(HRTF)、混響器(Reverberation)和交越干擾消除系統(CCS)，本研究主要在探討多種喇叭陣列的交越干擾消除系統。使用逆濾波器和正規化(Regularization)的方法設計多通道數位濾波器來消除人耳和喇叭間的交越干擾。為了降低計算負載，使用多率訊號處理(Multirate signal processing)的方法達成限頻寬(Band-limited)的目的。更進一步地使用陣列訊號處理中聲束操控(Beam-steering)技術來鎖住人的雙耳。本文提出兩種更容易且更有效率的方法，分別為Lagrange內插和多率訊號處理。模擬和實驗的結果顯示，本文提出的系統能有效地重建3D虛擬音場並能夠即時的實現達到影音同步的目的。

A personal 3-D virtual cinema based on panel speaker arrays is presented in this paper. This system is built on a personal computer for a single user. It is capable of rendering sound images positioned arbitrarily around a listener, synchronizing with the video image. The implemental techniques consist of the head related transfer function (HRTF), the reverberation, and the cross-talk cancellation system (CCS). This paper is focused on the CCS based on various speaker arrays. An inverse filtering and regularization technique is employed in designing multi-channel digital filters to cancel the cross-talks between the speakers and the listener’s ears. The band-limited implementation using multirate approach is employed to minimize the computation loading. Furthermore, a beam-steering technique in array signal processing is introduced to track the head motion. Multirate scheme and Lagrange interpolation are used to synthesize fractional delays involved in beam-steering. The system is implemented on the platform comprising various panel speaker arrays and a personal computer with a multi-channel sound card. Numerical simulation and experimental investigation indicated that the proposed system is effective in creating an immersive 3D sound image, synchronizing with the video image.