1. Date of download: 9/20/2016 Copyright © ASME. All rights reserved. From: Transmission Loss of Variable Cross Section Apertures J. Vib. Acoust. 2014;136(4):044501-044501-5. doi:10.1115/1.4027402 Schematic identifying variables for an aperture with the entry on the left and exit on the right Figure Legend:

2. Date of download: 9/20/2016 Copyright © ASME. All rights reserved. From: Transmission Loss of Variable Cross Section Apertures J. Vib. Acoust. 2014;136(4):044501-044501-5. doi:10.1115/1.4027402 Acoustic finite element model of a uniform cross-sectional area aperture with diffuse acoustic field excitation at the entry and radiation impedance at the aperture entry and exit Figure Legend:

3. Date of download: 9/20/2016 Copyright © ASME. All rights reserved. From: Transmission Loss of Variable Cross Section Apertures J. Vib. Acoust. 2014;136(4):044501-044501-5. doi:10.1115/1.4027402 Transmission loss of a circular aperture with radius of 5.64 mm and length of 10 cm. For the acoustic FEM, the element length is 0.7 mm with 257,474 nodes (quadratic tetrahedral elements). Fifty four acoustic modes were included in the forced response analysis. Figure Legend:

4. Date of download: 9/20/2016 Copyright © ASME. All rights reserved. From: Transmission Loss of Variable Cross Section Apertures J. Vib. Acoust. 2014;136(4):044501-044501-5. doi:10.1115/1.4027402 Transmission loss for uniform cross section apertures having the same cross-sectional area but different shape Figure Legend:

5. Date of download: 9/20/2016 Copyright © ASME. All rights reserved. From: Transmission Loss of Variable Cross Section Apertures J. Vib. Acoust. 2014;136(4):044501-044501-5. doi:10.1115/1.4027402 Schematic showing a conical aperture and variables. r2 and L are held constant at 5.64 mm and 100 mm, respectively. Figure Legend:

6. Date of download: 9/20/2016 Copyright © ASME. All rights reserved. From: Transmission Loss of Variable Cross Section Apertures J. Vib. Acoust. 2014;136(4):044501-044501-5. doi:10.1115/1.4027402 Transmission loss for converging and diverging cones. For the converging case, r1 and r2 are 22.56 mm and 5.64 mm, respectively. For the diverging case, r1 and r2 are 5.64 mm and 22.56 mm, respectively. For the acoustic FEM, the element length is 1 mm with 527,924 nodes (quadratic tetrahedral elements). Two hundred and sixty eight acoustic modes were included in the forced response analysis. Figure Legend:

7. Date of download: 9/20/2016 Copyright © ASME. All rights reserved. From: Transmission Loss of Variable Cross Section Apertures J. Vib. Acoust. 2014;136(4):044501-044501-5. doi:10.1115/1.4027402 Effect of radius ratio on the transmission loss of a conical aperture; r = 5.64 mm Figure Legend:

8. Date of download: 9/20/2016 Copyright © ASME. All rights reserved. From: Transmission Loss of Variable Cross Section Apertures J. Vib. Acoust. 2014;136(4):044501-044501-5. doi:10.1115/1.4027402 Schematic showing an aperture with abrupt contraction. l1 and l2 are each 50 mm and r is 5.64 mm. Figure Legend:

9. Date of download: 9/20/2016 Copyright © ASME. All rights reserved. From: Transmission Loss of Variable Cross Section Apertures J. Vib. Acoust. 2014;136(4):044501-044501-5. doi:10.1115/1.4027402 Effect of radius ratio (R/r) on the transmission loss for an aperture with abrupt cross-sectional area change Figure Legend:

10. Date of download: 9/20/2016 Copyright © ASME. All rights reserved. From: Transmission Loss of Variable Cross Section Apertures J. Vib. Acoust. 2014;136(4):044501-044501-5. doi:10.1115/1.4027402 Transmission loss determined by acoustic finite element analysis and compared with measured results [23] for aperture with 6 cm × 13 cm cross section and length of 30 cm. The cutoff frequency is approximately 1310 Hz. For the acoustic FEM, the element length is 5 mm with 186,819 nodes (quadratic tetrahedral elements). Four hundred and eighty two acoustic modes were included in the forced response analysis. Figure Legend: