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Different sound decay patterns and energy feedback in coupled volumes
Hongjie Pu1, Xiaojun Qiu, Jiqing Wang
1Key Laboratory of Modern Acoustic, Institute of Acoustics, Nanjing University, Nanjing 210093, China. puhongjie@nju.edu.cn
The Journal of the Acoustical Society of America
|April 12, 2011
Summary
Sound decay in coupled rooms is not confined to physical boundaries. Concave double sloped decays originate within the more reverberant sub-room, influenced by reverberation differences and energy feedback.
Area of Science:
- Acoustics
- Architectural Acoustics
- Sound Propagation
Background:
- Coupled rooms exhibit distinct non-exponential sound decays, like concave and convex double sloped decays.
- These decays are traditionally attributed to specific sub-room reverberation characteristics and physical boundaries.
Purpose of the Study:
- To investigate the actual location and influencing factors of non-exponential sound decays in coupled rooms.
- To analyze sound energy flow and its role in shaping decay characteristics.
Main Methods:
- Numerical simulations of sound fields in coupled room configurations.
- Experimental validation of simulation results.
- Analysis of sound energy flow patterns across different room regions.
Main Results:
- The demarcation line for concave and convex double sloped decays is located within the more reverberant sub-room, not at physical boundaries.
- Sound field penetration into auxiliary sub-rooms is dependent on the difference in natural reverberations.
- Energy feedback mechanisms within the room system directly contribute to concave double sloped decays.
Conclusions:
- Non-exponential sound decay phenomena in coupled rooms are more complex than previously assumed.
- The reverberant sub-room plays a critical role in determining decay characteristics.
- Understanding energy feedback is key to explaining concave double sloped decay patterns.
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