TESTING AND CHARACTERIZATION OF SECOND-ORDER DIFFERENTIAL MICROPHONES

1.2 First and Second-Order Directional Microphones......Page 17
1.3 Ormia Design......Page 23
1.5 Overview and Organization......Page 26
2.1 Overview......Page 28
2.2 Lumped Parameter Model......Page 29
2.3 Directivity Index......Page 31
2.4 Characterization......Page 33
3.2 Current Techniques......Page 35
3.3 Alternate Approaches for Measuring Sound Fields......Page 36
4.1 Accuracy of Pressure Measurements......Page 44
4.2 Accuracy of Positioning System......Page 45
4.3 Spacing Issues......Page 47
4.5 Issues at Low Frequencies: Small Gradients......Page 49
5.1 Measuring Ormia Differential Microphones......Page 51
5.2.1 Introducing the Estimation Problem......Page 53
5.2.2 The Linear Model......Page 54
5.2.3 Theoretical Data Collection......Page 56
5.2.4 Cramer-Rao Lower Bound......Page 59
5.2.5 Least Squares Estimation......Page 61
5.2.6 Simulation of Experiment......Page 64
5.2.7 Measurement Versus Estimation......Page 68
5.3 Simulated Plane Wave Response......Page 71
MATLAB CODES......Page 85
RESULTS OF LAGRANGE POLYNOMIAL USING 25-POINT STENCIL......Page 109