From the guidelines of EPD,the major function of noise barrier is to eliminate the excessive noise generated by vehicles. Noise barriers are considered as the most reasonable and efficient noise mitigation measures. Many factors need to consider in design of noise barrier. They are Acoustical Design Consideration, Transmission Loss of Various Barrier Materials, in Noise Barrier Performance due to Holes, Slits or Gap, Barrier Shape ,Choice of Material ,barrier materials
,Earth Berms and Retaining Structures and Non-acoustical Consideration. This report first to introduce the eight considerations listed on above and give the case study of noise barrier in Hong Kong to make a analysis to know is it excellent or not.
Acoustical Design Consideration
Acoustical performance is related to material,location,dimensions and shape of noise barrier. Normally,noise from the road traffic mainly reflected by noise barrier toward the source and some of the noise are absorbed by the barrier or diffracted at the top edge of barrier. The diffraction of the noise mainly depends on the location, shape and dimensions of barriers. The lower portion of absorptive materials should at least two to three meters. It ensure the materials would absorb most of the noise energy.
Transmission loss of various barrier materials
It is acknowledged that all materials permit sound energy to pass through, it depends on the material and frequency of sound.”Transmission Loss” is the attenuation of sound passing through a material. For acoustical purposes , the materials used for barrier between noise source and noise receiver as long as it has a TL of at least 10dB greater than the desire noise reduction. It ensures that the only nise path to be considered in acousti...
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...ge to the ecosystem and environmental like the phenomenon shows in case II. Indeed, case II is a failure design.
(Magazine of HKBWS)
To sum up , compare with case I and case II ,choice of material is a important part for design consideration. It is necessary to understand the geographical conditions and make a correct choice of materials. For case II, non-transparent materials should be used like concrete , that reduce the chance of the birds collide to the barrier. In the future , government can take case I as the role model for designing noise barrier. Since case I can construct it self with natural growth of grass, it is environmental friendly. Last but not least, it is necessary to base on the eight design consideration of EPD guideline.
Works Cited
http://www.epd.gov.hk/epd/english/environmentinhk/noise/guide_ref/design_barriers_content2.html
The purpose of this experiment was to determine whether if the sound is affected when it travels through different length pipes. The method used to do this experiment was created by using 5 different PVC pipes in the lengths of 10, 20, 30, 40, and 50 centimeters. Then, using a tuning fork, sound will be produced on one end of the PVC pipe and measured with a decimeter on the other end. This experiment was recorded using 5 trials for each independent level and the average decibels (dB) for each pipe length were recorded.
...kes a great argument showing us how the positive results outweigh the negative. Contamination isn’t so bad after all.
The data we found supported our original water hypothesis. My group and I believed that adding ammonium nitrate into our eco-column would ultimately damage the ecosystems. The increase in levels of minerals from the aquatic ecosystem also indicates that the entire column was being destroyed. Through this experiment, I have learned that too much nutrients and minerals within an ecosystem can be extremely harmful to the wildlife. Throughout this experiment the water in our eco column began to turn yellow because of a surplus of nitrogen and phosphorous in the eco-column. In some of the eco-columns of the other groups in the classroom, they had eutrophication in the early stages of their eco-column which resulted in the death of many of their
For most careers, sound is used as a medium for communicating thoughts, ideas, and important information. For this very reason, it is unlikely that you would ever see an office space with tall ceilings and hardwood floor—as people would be unable to clearly communicate with each other due to the echoic effects of the architectural structure. Instead, office spaces have relatively low ceilings and carpeted floor to reduce the number of reflections from a sound source. This allows our voices to be heard clearly for the intended audience—whether a cubicle neighbor, or a group of people in a conference room. However, a large number of industrial workplaces produce sound pollution as a result of machinery. For these particular environments, sound absorption and isolation techniques are used to reduce noise pollution and create safer aural environments for employees. With this concept of utilizing sound and disposing sound, we can take a closer look at a career in music production—a job that meticulously considers every aspect of sound. While the engineers that produce ‘billboard albums’ rely greatly on their choice of equipment and their ears, the environment in which they record, mix and master plays a tremendous role in the clarity and the overall soundscape.
Bleifuss, Joel. "A Deadly Disorder at the EPA." In These Times. Mar. 2013: p. 20. SIRS Issues Researcher. Web. 03 Apr. 2014.
This lab experiment was conducted in order to test the speed of sound, which is the distance traveled per unit time by a sound wave. This experiment was carried out with a certain setup, which involved materials such as a computer, a Logger Pro, a vernier microphone, two tubes, a temperature probe, a meter stick, and a dog trainer clicker. These materials were set up in a specific fashion, the Logger Pro was connected to the computer, which allowed for a temperature reading. The microphone was then connected to the lab interface and the two tubes were taped together from one end. One end of the tube was then placed against a wall, the microphone positioned near the open end of the tube as the dog clicker was pressed. Once the clicker was pressed, the speed of the sound traveling through the tube was collected by the microphone, the data then was inputted into the computer by the Logger Pro.
Exton, Peter, “The Room Acoustics of the Guangzhou Opera house”, Harold Marshall Group Consultant 2010, Marshall Day Acoustics
The noise of Aircrafts was historically a major environmental issue for the airline. It is still high on the agenda of public concern. Noise disturbance has a variety of difficult issues to assess because it is open for self- reactions. Its impact is not one permanently on the actual environment, but it can have many effects on the people living in the area of the airport, including: interference in c...
... middle of paper ... ... Designs, C. & B. 2013. ProSonic Acoustic Cubes -. [online] Available at: http://www.customaudiodesigns.co.uk/acoustic-cubes.htm [Accessed: 1 Dec 2013].
For many people, the noise from the turbines is unbearable, and that’s something else that should be taken into consideration.
over great distances, causing adverse effects such as acid rain in areas far from the
people find noisy vehicles a great disturbance to have around the streets. If there is something
What are the pollutants involved? 4. What are the consequences? Write in detail consequences on the Environment, on local people and the economy of the country. 5.
the Effect of Urban Noise on the Active Space of Avian Vocal Signals. It explains how
...or lakes (Weber 2). When people just dump waste products instead of recycling, it is a misuse of the soil and can contribute to serious health conditions in animals, plants and humans.