在傳統立體聲道錄音的方法，都是以機械構造設計來產生全向、雙極和心型的獵槍式麥克風，例如中-側邊型立體聲道錄音和X-Y立體聲道錄音，體積較大，不易製作於可攜帶式的電子產品中，因此本研究利用消費型電子產品中常用的微機電麥克風提出新的立體聲錄音設計，且微機電麥克風具有較小體積的優點。將多顆微機電麥克風排列成不同的陣列形狀，搭配不同的指向性演算法來產生雙指向性收音之效果，利用兩個不同方位的指向性，錄製左右邊的聲源以達到立體聲道錄音。本研究所提出垂射陣列立體聲錄音、耦合型立體聲錄音、解耦合型立體聲錄音和曲線型立體聲錄音的設計，並藉由主觀測試、客觀測試和麥克風不匹配測試來評估不同的立體聲錄音性能。
本研究所提出之設計可以與傳統獵槍式麥克風立體聲錄音達到相同甚至更好的立體聲錄音效果，更是比獵槍式麥克風來的更小以及更輕量化。尤其是在安靜的環境中，垂射陣列立體聲錄音評估效能中是最好的，而在吵雜的環境中，曲線型立體聲錄音評估效能是最好的。

In traditional stereo recording methods which are based on the design of mechanical structure to generate omnidirectional, dipole and cardioid shotgun microphone, such as Mid-Side stereo recording and X-Y stereo recording. In general, the size of shotgun microphones is relatively large. Therefore, the MEMS microphone benefited from its small size and capability are used in this research to construct a novel stereo recording system. With MEMS microphones arranged into different array format, different beamforming algorithms are able to generate two directivity patterns at designed angles of mainlobe for the left and right channels. The proposed designs including broadside array, coupled array, decoupled array and curved array recording design are evaluated by objective, subjective, and mismatch tests. Throughout performance evaluations, we know that the recording performance by the MEMS microphone array with specific algorithms is the same as, even better than, that by shotgun microphones. Especially, the broadside array and curved array designs yield the highest recording performance in silent and noisy circumstances, respectively.

摘 要 I
ABSTRACT II
致 謝 III
LIST OF TABLE V
LIST OF FIGURES VI
I. INTRODUCTION 1
II. FARFIELD BEAMFORMERS 4
A. Array signal processing basics 4
B. Performance measures 9
1. Directive index 9
2. White noise gain 10
C. Beamformer design 11
1. Fourier beamformer 11
2. First-order differential microphone array 14
3. Superdirective array design 16
4. Convex optimization algorithm design 19
III. STEREO AND 5.1 CHANNEL RECORDING USING BEAMFORMING APPROACHES 21
A. Mid-Side stereo recording 21
B. X-Y stereo recording 22
C. Broadside array design 22
D. Coupled array design 23
E. Decoupled array design 23
F. Curved array design 24
G. 5.1 channel recording 25
H. Simulation results 26
IV. PERFORMANCE EVALUATION 26
A. Objective test 27
1. Channel separation 27
2. Interaural level difference 28
B. Subjective test 29
1. Listening test 29
C. Mismatch test 31
V. CONCLUSIONS AND FUTURE WORK 33
A. Conclusions 33
B. Future work 35
REFFERENCES 36

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