Related Experiment Video
Updated: Aug 29, 2026

A Simple Approach to Perform TEER Measurements Using a Self-Made Volt-Amperemeter with Programmable Output Frequency
Published on: October 5, 2019
Sound transmission characteristics of Tee-junctions and the associated length corrections
1Department of Building Services Engineering, The Hong Kong Polytechnic University, Hong Kong, China. besktang@polyu.edu.hk
Abstract:
The sound transmission characteristics of a Tee-junction formed by a sidebranch and an infinitely long duct are investigated numerically using the finite element method. The associated corrections of the branch length and the upstream duct length are also discussed in detail. The types of branch resonance that result in strong or weak sound transmission across the junction are determined and their effects on the length corrections examined. Results suggest that the type of sidebranch, the branch width, the branch length, and the order and the form of the resonance affect more significantly the length corrections of the duct section. The excitation of nonplanar higher branch modes gives rise to rapid increase in the duct length corrections and also results in lower sound transmission.
Related Concept Videos
Transmission Line Design Considerations
Boundary Conditions: Lossless Lines
At the receiving end, the boundary condition states that the voltage equals the product of the receiving-end impedance and current. This relationship is expressed as a function of the incident and...
Lossless Lines
Transmission-Line Differential Equations
Line Section Model
A circuit representing a line section of length Δx helps in understanding the transmission line parameters. The voltage V(x) and current i(x) are measured from the...
Interference: Path Lengths
Two special sources may be considered when they are in phase. This can be easily achieved by feeding the two sources from the same source. An example would be synchronizing the two speakers by feeding them with the same source, such as the sound waves produced by a tuning fork. This setup ensures that the two sources have the same frequency and are...
Biasing of Metal-Semiconductor Junctions
In Schottky junctions, where the semiconductor is n-type, applying a positive voltage to the metal relative to the semiconductor reduces its Fermi...

