Sound Transmission Loss of Thick Perforated Panels

2001 ◽  
Vol 8 (1) ◽  
pp. 41-56 ◽  
Author(s):  
K. T. Chen ◽  
S. H. Jan
Keyword(s):  
Theoretical Analysis ◽  
Critical Frequency ◽  
Transmission Loss ◽  
Sound Transmission ◽  
Sound Intensity ◽  
Sound Transmission Loss ◽  
Coincidence Effect ◽  
Maximum Discrepancy

A study is reported of the sound transmission loss of perforated panels. The study includes a theoretical analysis and measurement by means of sound intensity. The predicted transmission loss is similar to that measured above 630 Hz. The maximum discrepancy is less than 2 dB. The perforation in a thick panel is found to reduce the coincidence effect at the critical frequency.

Acoustic Parts in Vehicle Sound Transmission Loss Test Method Research

2013 ◽  
Vol 380-384 ◽  
pp. 73-76
Author(s):  
Xiu Feng Wang ◽  
Jie Shi
Keyword(s):  
Sound Pressure ◽  
Transmission Loss ◽  
Sound Transmission ◽  
Sound Intensity ◽  
Pressure Level ◽  
Test Method ◽  
Intensity Level ◽  
Sound Transmission Loss ◽  
Passenger Compartment ◽  
Exterior Panel

The sound transmission loss (STL) of the acoustic parts in the vehicle was proposed to be computed using the Sound Pressure Level measured at the several locations inside the vehicle and the transmitted Sound Intensity Level on the vehicles exterior panel, which the acoustic treated vehicle passenger compartment is assumed as a small reverberation room. The necessary parts retrofits and acoustic treatments for Sound transmission loss tests of the acoustic parts in the vehicle were listed. The values of the appropriate number and positions of the loud speakers, microphones and sound intensity probes for Sound transmission loss of the acoustic parts in the vehicle were recommended. The in vehicle sound transmission loss tests of the acoustic parts such as the doors, carpets, wheel house etc. were achieved in the semi-anechoic room. Based on the door system, the correlation work has been done among the methods of the proposed in vehicle STL test, the reverberation - semi-anechoic chamber buck STL test and SEA analysis.

Observations on the Systematic Deviations between Two Methods of Measuring Sound Transmission Loss

1996 ◽  
Vol 3 (1) ◽  
pp. 1-11 ◽  
Author(s):  
F. Jacobsen ◽  
H. Ding
Keyword(s):  
Measurement Errors ◽  
Transmission Loss ◽  
Sound Transmission ◽  
Sound Field ◽  
Sound Intensity ◽  
Field Method ◽  
Sound Transmission Loss ◽  
Careful Measurement ◽  
Linear Decay ◽  
Comparable Size

The paper examines and discusses possible explanations of the systematic deviations between conventional and intensity-based sound transmission loss measurements frequently reported in the literature. Both the conventional diffuse-field method and the method based on the sound intensity technique are subject to several systematic errors of comparable size. The sources of error include non-linear decay functions, the absorption of the partition itself, and intensity measurement errors, which are aggravated by the fact that the sound field conditions are usually fairly difficult. It is concluded that with very careful measurement procedures there are no systematic deviations.

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