What is Noise? In daily life, noise means unwanted sound.

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1 NAME PIYUSH ZINZALA DHAVAL KARKAR JEEGAR VARIYA YASH BANKER CHINTAN BAROT ROLL NO. 14SA162 14SA122 14SA134 14SA180 14SA120

2 What is Noise? In daily life, noise means unwanted sound. As you have no doubt experienced, unwanted sounds can include distractions, sounds that are loud enough to damage hearing and even sound leakage that could affect privacy. In architecture, one of the many goals of the designer is to create rooms and buildings that maximize sound performance. This means that unwanted sounds should be prevented, and desired sounds should be enhanced.

3 Health Effects According to the USEPA, there are direct links between noise and health. Also, noise pollution adversely affects the lives of millions of people. Noise pollution can damage physiological and psychological health. High blood pressure, stress related illness, sleep disruption, hearing loss, and productivity loss are the problems related to noise pollution. It can also cause memory loss, severe depression, and panic attacks.

4 Sources of Noise Pollution Transportation systems are the main source of noise pollution in urban areas. Construction of buildings, highways, and streets cause a lot of noise, due to the usage of air compressors, bulldozers, loaders, dump trucks, and pavement breakers. Industrial noise also adds to the already unfavorable state of noise pollution. Loud speakers, plumbing, boilers, generators, air conditioners, fans, and vacuum cleaners add to the existing noise pollution. Planting bushes and trees in and around sound generating sources is an effective solution for noise pollution. Regular servicing and tuning of automobiles can effectively reduce the noise pollution. Buildings can be designed with suitable noise absorbing material for the walls, windows, and ceilings. Workers should be provided with equipments such as ear plugs and earmuffs for hearing protection.

5 Solutions for Noise Pollution Similar to automobiles, lubrication of the machinery and servicing should be done to minimize noise generation. Soundproof doors and windows can be installed to block unwanted noise from outside. Regulations should be imposed to restrict the usage of play loudspeakers in crowded areas and public places. Factories and industries should be located far from the residential areas. Community development or urban management should be done with long-term planning, along with an aim to reduce noise pollution. Social awareness programs should be taken up to educate the public about the causes and effects of noise pollution.

6 What is Noise? Difference Between Noise and Sound Intensity Level Noise is a subjective and relative perception, but sound intensity level is a scientific measure of the power of sound. Even if a sound source has a relatively low sound intensity level, some individuals might find a certain frequency of sound wave annoying because the human ear reacts differently to different frequencies of sound (pitches) and the hearing ability of individuals is subjective. Sound intensity level can only be used as a standard to identify the volume of sound that could cause hearing damage. It does not represent the exact perception of the sound to individuals.

7 What is Noise? Sound Transmission in Architecture Sources of Noise The two major sources of noise in architecture are: 1.Airborne noise, or sound waves transmitted from a source to a receiver through the air. 2.Structure-borne noise is caused by vibration from within the building caused by footsteps or machines. The vibration is directly transferred through the building s structures and materials. A B C A. The sound of a plane s engine is a kind of exterior airborne sound that may affect communities near airports. B. The MTR s operating systems are quiet, but the vibration of the train rail generates exterior structure-borne noise. C. In a gymnasium, cheering spectators may cause interior airborne noise to the surrounding rooms, while the athletes activities generate interior structure-borne noise.

8 What is Noise? Sound Transmission in Architecture

9 What is Noise? Noise transmission paths Sound waves travel from the source to the receiver via multiple paths. Altering the paths of sound transmission is a common way to control noise in architecture. When sound strikes on a surface, part of the sound reflects off the wall surface back into the space, and part of it is transmitted through the wall to the space beyond. Flanking transmission of sound Flanking transmission is the propagation of sound wave via building elements. An air gap can stop the transmission of sound effectively. [Discussion] How is unwanted sound transmitted in this diagram?

10 Noise Control through Architectural Design Possible Perspectives Sound reduction required from the meeting room = db = 10dB Sound reduction required from the nearby sports courts = db = 45dB The wall of the meeting room should have a Sound Reduction Index ranging from 10 db to 45 db. According to the graph of Sound Reduction Index, three building materials could be suitable for the meeting room: 50 mm Plastered Breeze Block (a light concrete building block made with cinder aggregate) 9 mm Glass 0.7 mm Sheet Steel After obtaining the data from an acoustic consultant, architects decide what materials should be used for the functions and aesthetics of the space. Other considerations include structural tolerance, environmental concerns and universal design for all users. Sound Reduction Index of common building materials (Source: Noise Control in Mechanical Services, 1972)

11 Noise Control through Architectural Design Possible Perspectives A double-leaf plywood wall could be constructed with a row of double-glazed operable clerestory windows for natural lighting and ventilation. Double-partition wall insulation When two sound barriers are completely separated and isolated from one another, sound insulating performance is enhanced. Sound absorption materials like mineral wool can be used to fill the cavity for extra sound insulation against flanking transmission. NAP Acoustics (Far East) Ltd Double-glazing An operable double-glazed window provides horizontally offset openings that allows natural ventilation while preventing direct propagation of traffic noise. The narrow path between the double window panes dissipates sound energy and lowers noise levels relatively.

12 Noise Control through Architectural Design Redirecting Sound away from Receivers Artificial noise screen Noise barriers can redirect the paths of noise away from receivers. They can be artificial (for example, a wall) or natural (a forest). One common application for noise barriers is to prevent traffic sounds from penetrating nearby neighborhoods or habitats. Sometimes noise barriers are integrated with the building design. Noise sensitive buildings like residential blocks may be built above a podium or a shopping mall that inhibits the transmission of noise to the apartments.

13 Noise Control through Architectural Design [Discussion] Can you identify the noise sources and barriers in the images and trace the sound transmission paths? Mark them on the following picture.

14 Noise Control through Architectural Design Kwai Tsing Theatre Kowloon s Kwai Tsing Theatre illustrates how architectural design can be used to protect quiet spaces against airborne and structure-borne noises from inside and outside the theatre. Its location next to the MTR railway and heavy traffic is particularly challenging given the requirements of the theatre s multifunctional spaces, which sometimes host simultaneous events.

15 Noise Control through Architectural Design Kwai Tsing Theatre Springs placed on the pile caps of the building can absorb exterior structure-borne noise before it is transmitted to the interior. Theatre and music rooms are built inside an isolated shield to reduce flanking transmission of noise.

16 Noise Control through Architectural Design Kwai Tsing Theatre Improving the Sound Reduction Index of the Structure The ceilings, walls and floors of the theatre are isolated from building structure by springs or resilient pads. An air gap around the floating floors and suspended ceilings also improves the Sound Reduction Index of the structure.

17 Noise Control through Architectural Design Case Study Kwai Tsing Theatre The air gap is the most important factor increasing it (rather than increasing the mass of the floors) would achieve greater reductions in noise as compared to increasing the mass of the structure or the floating floor.

18 Thank you