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Orientation and exploration: Taking green city as the goal to develop new forms of housing development
Published in Mohd Johari Mohd Yusof, Junwen Zhang, Advances in Civil Engineering: Structural Seismic Resistance, Monitoring and Detection, 2023
One of the most commonly applied technologies to lower noise levels is the ANC (active noise control) system, which can produce reversed sound to counter the original noise. The current situation is that traditional ANC, such as Single-Channel Duct-Type Open-Window ones (Wongeun Oh, 2017), performs badly in mitigating low-frequency noise. It is most efficient under the frequency of 400 Hz to 1800 Hz. Another ANC window design that applies micro-perforated absorbers performs well when the sound is between 500 Hz and 800 Hz but makes little difference to noise with low frequency (Lam et al. 2020).
Total Exposure Hearing Health Preservation
Published in Kirk A. Phillips, Dirk P. Yamamoto, LeeAnn Racz, Total Exposure Health, 2020
The traditional hierarchy of controls paradigm can also be employed for hearing health. Removing the noise source, whether at work or not, reduces risk. Engineered controls for noise are well-understood, and many acoustics companies specialize in noise control. From a consumer product perspective, market forces can drive manufacturers to control noise in their products. NIOSH has worked on its “Buy Quiet” program for many years, to include developing standards for product noise (Beamer et al. 2016, Camargo et al. 2017). From the acquisition standpoint, the USDOD specifies noise standards for new systems in MIL-STD-1474E. After a noise source is present in the environment, effective passive controls can be devised and constructed sometimes for little capital investment (Sweeney et al. 2010). The field of active noise control (ANC), sampling noise and then adding an out-of-phase noise to effectively decouple the acoustic energy from the medium it travels through, can also reduce noise. ANC application works best in a volume-constrained problem and best for lower frequency noise (<500 Hz) (Hansen 1999). While practicing occupational hygienists can implement ANC controls, they tend to be expensive and specific to the particular noise situation (Slagley and Guffey 2006, 2007a, 2007b). As further evidence that markets drive innovation, ANC earmuffs have found a comfortable niche among consumers.
Acoustic Signal Processing
Published in Richard C. Dorf, Circuits, Signals, and Speech and Image Processing, 2018
Juergen Schroeter, Gary W. Elko, M. Mohan Sondhi, Vyacheslav Tuzlukov, Won-Sik Yoon, Yong Deak Kim
Active noise control (ANC) is a way to reduce the sound pressure level of a given noise source through electroacoustic means. ANC and echo cancelation are somewhat related. While even acoustic echo cancelation is actually done on electrical signals, ANC could be labeled “wave cancelation,” since it involves using one or more secondary acoustic or vibrational sources. Another important difference is the fact that in ANC one usually would like to cancel a given noise in a whole region in space, while echo cancelation commonly involves only one microphone picking up the echo signal at a single point in space. Finally, the transfer function of the transducer used to generate a cancelation (“secondary source”) signal needs to be considered in ANC.
A Robust Adaptive Filter for Diffusion Strategy-based Distributed Active Noise Control
Published in IETE Journal of Research, 2023
Active noise control (ANC) often called noise cancellation employs the destructive interference idea to create other sound sources that cancel out the originating noise [7,8]. ANC systems utilize WASNs to improve and distribute processing burdens across the nodes [9]. ANC nodes are composed of microphones that detect errors, loudspeakers that transmit anti-noise signals, and CPUs that can process and communicate with each other nodes [10].