Acoustics


 * Definitions: **

Speed: Distance travelled in unit time (m/s). Frequency: Number of complete waves in one second (Hz). Wavelength: Distance between matching poins on the wave (m). Longitudinal: Vibration parallel to direction of travel. Transverse: Vibration of rigth angle to direction of travel.

 **All about Sound** Room acoustics are about the way in which sound behaves in a room. Sound transmission, sound absorption, sound reflection and sound diffusion are all aspects that are important here. Room acoustics also include how we as humans perceive different acoustic phenomena. The field of building acoustics covers sound insulation too, where the route that the sound takes from the room to other areas is included.

 ** Room acoustic descriptors **  As regards acoustic design, it is an advantage if different designs and procedures can be evaluated objectively. For this purpose, a number of measurable room acoustic descriptors have been defined. These descriptors can be used to formulate room acoustic specifications and to check the effect of different procedures. It would, of course, have been an advantage to have only one descriptor that works in all rooms. But hearing is multidimensional, so several descriptors are required.  ** Room acoustic descriptors ** ||
 * [[image:http://www.ecophon.com/Templates/Ecophon/Handlers/IR.ashx?T=TL&P=/Global/fodoc/519fa28a-faae-4f53-9bb0-9f617150f0da.jpg&PI=10080&PL=en]] || __Reverberance__  Reverberance is linked to the speed at which sound energy disappears in a room. An unfurnished room with hard surfaces, such as a church, is perceived as being more reverberant than a well-furnished living room.

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 * [[image:http://www.ecophon.com/Templates/Ecophon/Handlers/IR.ashx?T=TL&P=/Global/fodoc/4a2c8eb0-cd5e-40e1-8142-94122a17c876.jpg&PI=10081&PL=en]] || __Speech clarity__  Speech clarity concerns the quality of speech transfer to the listeners. In a reverberant room with disturbing background noise, it can be difficult to pick up speech.

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 * [[image:http://www.ecophon.com/Templates/Ecophon/Handlers/IR.ashx?T=TL&P=/Global/fodoc/84f478be-b8b8-4ae2-9d55-45f10fbe1215.jpg&PI=10082&PL=en]] || __Auditory strength__  Auditory strength is the level at which we experience sound. A reverberant room gives a higher sound level than a room with added sound absorption.

|| ** What is sound insulation? ** ** What is sound insulation? **  || || || ||  ** Room Acoustic Design ** || || ||  ||
 * [[image:http://www.ecophon.com/Templates/Ecophon/Handlers/IR.ashx?T=TL&P=/Global/fodoc/c8acc8cf-573f-4ecc-a065-acc3ffddbd41.jpg&PI=10083&PL=en]] || __Spatial decay__  The sound level decreases as the distance from the sound source increases. The design of the room (shape, furnishing, surface finish etc.) influences the extent to which the sound level decreases along with the distance.
 * [[image:http://www.ecophon.com/Templates/Ecophon/Handlers/IR.ashx?T=TL&P=/Global/07.Illustrations%20-%20Descriptive/Room%20Acoustic%20Comfort/Room-to-room_insulation.jpg&PI=10343&PL=en]] || __Room-to-room insulation__  How to avoid unwanted sounds from adjacent rooms.
 * [[image:http://www.ecophon.com/Templates/Ecophon/Handlers/IR.ashx?T=TL&P=/Global/07.Illustrations%20-%20Descriptive/Room%20Acoustic%20Comfort/One-way_sound_insulation.jpg&PI=10344&PL=en]] || __One-way sound insulation__  Suspended acoustic ceilings help to avoid noise coming from installations.
 * [[image:http://www.ecophon.com/Templates/Ecophon/Handlers/IR.ashx?T=TL&P=/Global/07.Illustrations%20-%20Descriptive/Room%20Acoustic%20Comfort/Vertical_airborne_sound_insulation.jpg&PI=10345&PL=en]] || __Vertical airborne sound insulation__  Airborne sound insulation may relate to sounds generated in both the room below and the room above.
 * [[image:http://www.ecophon.com/Templates/Ecophon/Handlers/IR.ashx?T=TL&P=/Global/07.Illustrations%20-%20Descriptive/Room%20Acoustic%20Comfort/Impact_sound_insulation.jpg&PI=10346&PL=en]] || __Impact sound insulation__  A suspended ceiling system can be used to improve the impact sound insulation and therefore reduce the impact sound level.
 * [[image:http://www.ecophon.com/Templates/Ecophon/Handlers/IR.ashx?T=TL&P=/Global/07.Illustrations%20-%20Descriptive/Room%20Acoustic%20Comfort/room_acoustic_comfort.jpg&PI=10370&PL=en]] || __Different acoustic room types__  The way sound behaves and affect the people in the room depends heavily on the room geometrie and placement of absorption material. Find out what acoustic room type you are working on.
 * [[image:http://www.ecophon.com/Templates/Ecophon/Handlers/IR.ashx?T=TL&P=/Global/07.Illustrations%20-%20Descriptive/Room%20Acoustic%20Comfort/sound_energy.jpg&PI=10337&PL=en]] || __Choosing the right sound absorption__  Using absoprtion class A means that less material is needed and quality of teaching, working and healing is optimised.
 * [[image:http://www.ecophon.com/Templates/Ecophon/Handlers/IR.ashx?T=TL&P=/Global/14.Concept%20Development/01.Office/Flash/Corridor-01.jpg&PI=10369&PL=en]] || __Acoustic design with wall panels and acoustical islands__  A fully covered absorbing ceiling is the preferred solution for placement of sound absorption material. Sometimes, the design might require additional or alternative solutions.
 * || __Room-to-room insulation__  How to avoid unwanted sounds from adjacent rooms.

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 * [[image:http://www.ecophon.com/Templates/Ecophon/Handlers/IR.ashx?T=TL&P=/Global/07.Illustrations%20-%20Descriptive/Room%20Acoustic%20Comfort/One-way_sound_insulation.jpg&PI=10344&PL=en]] || __One-way sound insulation__  Suspended acoustic ceilings help to avoid noise coming from installations.

||
 * [[image:http://www.ecophon.com/Templates/Ecophon/Handlers/IR.ashx?T=TL&P=/Global/07.Illustrations%20-%20Descriptive/Room%20Acoustic%20Comfort/Vertical_airborne_sound_insulation.jpg&PI=10345&PL=en]] || __Vertical airborne sound insulation__  Airborne sound insulation may relate to sounds generated in both the room below and the room above.

||  ** Room Acoustic Design ** ||
 * [[image:http://www.ecophon.com/Templates/Ecophon/Handlers/IR.ashx?T=TL&P=/Global/07.Illustrations%20-%20Descriptive/Room%20Acoustic%20Comfort/Impact_sound_insulation.jpg&PI=10346&PL=en]] || __Impact sound insulation__  A suspended ceiling system can be used to improve the impact sound insulation and therefore reduce the impact sound level.
 * [[image:http://www.ecophon.com/Templates/Ecophon/Handlers/IR.ashx?T=TL&P=/Global/07.Illustrations%20-%20Descriptive/Room%20Acoustic%20Comfort/room_acoustic_comfort.jpg&PI=10370&PL=en]] || __Different acoustic room types__  The way sound behaves and affect the people in the room depends heavily on the room geometrie and placement of absorption material. Find out what acoustic room type you are working on.

||
 * [[image:http://www.ecophon.com/Templates/Ecophon/Handlers/IR.ashx?T=TL&P=/Global/07.Illustrations%20-%20Descriptive/Room%20Acoustic%20Comfort/sound_energy.jpg&PI=10337&PL=en]] || __Choosing the right sound absorption__  Using absoprtion class A means that less material is needed and quality of teaching, working and healing is optimised.

||
 * [[image:http://www.ecophon.com/Templates/Ecophon/Handlers/IR.ashx?T=TL&P=/Global/14.Concept%20Development/01.Office/Flash/Corridor-01.jpg&PI=10369&PL=en]] || __Acoustic design with wall panels and acoustical islands__  A fully covered absorbing ceiling is the preferred solution for placement of sound absorption material. Sometimes, the design might require additional or alternative solutions.

 **Interview: Professor Murray Hodgson**  **Note taking**  Acoustical spaces, psycho acoustics  Sound in a space is noise? Usefull sound or bad sound  Echoing affects the sound in a room <span style="background-color: #ffffff; color: #444444; font-family: 'Segoe UI','Lucida Grande',Arial; vertical-align: baseline;"> Noisy place = bad acoustic design? Depends on the point of view <span style="background-color: #ffffff; color: #444444; font-family: 'Segoe UI','Lucida Grande',Arial; vertical-align: baseline;"> Sometimes noise is usefull because it gives a little more privacy. If we quit all the noise, probably we will fell like everybody can hear us <span style="background-color: #ffffff; color: #444444; font-family: 'Segoe UI','Lucida Grande',Arial; vertical-align: baseline;"> Noise is unwanted sound <span style="background-color: #ffffff; color: #444444; font-family: 'Segoe UI','Lucida Grande',Arial; vertical-align: baseline;"> A building is a physical system but the users are not <span style="background-color: #ffffff; color: #444444; font-family: 'Segoe UI','Lucida Grande',Arial; vertical-align: baseline;"> Requeriments for the needs of the people. You can’t cause auditive damage. This could also affect the emotions. <span style="background-color: #ffffff; color: #444444; font-family: 'Segoe UI','Lucida Grande',Arial; vertical-align: baseline;"> It’s needed to be carefull with sound reflection in certain places. <span style="background-color: #ffffff; color: #444444; font-family: 'Segoe UI','Lucida Grande',Arial; vertical-align: baseline;"> Depends of the priorities. Health is primordial when designing a building. <span style="background-color: #ffffff; color: #444444; font-family: 'Segoe UI','Lucida Grande',Arial; vertical-align: baseline;"> There’s no need to be extremist. Nobody wants to be in a concert hall and feel totally isolated <span style="background-color: #ffffff; color: #444444; font-family: 'Segoe UI','Lucida Grande',Arial; vertical-align: baseline;"> The noise can reduce the quality of life. <span style="background-color: #ffffff; color: #444444; font-family: 'Segoe UI','Lucida Grande',Arial; vertical-align: baseline;"> The acoustical environment specially of a building is something that can be designed with the architectural forms, the materials and the right equipment. <span style="background-color: #ffffff; color: #444444; font-family: 'Segoe UI','Lucida Grande',Arial; vertical-align: baseline;"> **Main idea** <span style="background-color: #ffffff; color: #444444; font-family: 'Segoe UI','Lucida Grande',Arial; vertical-align: baseline;"> The interview is about the point of view of a physic, Prof. Murray Hodgson, in the area of acoustics. He gives us the opinion of a scientist about the acoustic in architecture. In physics, buildings are physical systems and in this sense, noise is unwanted sound, but the problema is that the users of a building are humans, not machines, so, is necesary to think in their needs, because, health and emotions are primordial. For him, the noise is caused basically for the echo and the sound reflection, but this can be avoid by taking care on the architectural forms, the isolating materials and the right equipment. He also says that a noisy place not necessarily implides a bad acoustic design, because in certain levels, noise can be used to give privacy to the people in a room. For example, if we are talking in a restaurant and suddenly the noise disappears, we wiil feel like everybody can hear us. In conclussion, the answer is in the equilibrium because noise can reduce the quality of life but also could be usefull in some environments.