1.0Historical Backround of Museum
CHAPTER ONE
1.0HISTORICAL BACKROUND OF MUSEUM
A museum is a "permanent institution in the service of society and of its development, open to the public, which acquires, conserves, researches, communicates and exhibits the tangible and intangible heritage of humanity and its environment, for the purposes of education, study, and enjoyment", as defined by the International Council of Museums. The UK Museums Association definition (adopted 1998) is:
“ / Museums enable people to explore collections for inspiration, learning and enjoyment. They are institutions that collect, safeguard and make accessible artifacts and specimens, which they hold in trust for society.”1.1. ETYOLOGY
The English "museum" comes from the Latin word, and is pluralized as "museums" (or, rarely, "musea"). It is originally from the GreekΜουσείον (Mouseion), which denotes a place or temple dedicated to the Muses (the patron divinities in Greek mythology of the arts), and hence a building set apart for study and the arts, especially the institute for philosophy and research at the Library established at Alexandria by Ptolemy I Soter c280 BCE. The first museum/library considered to be the one of Plato in Athens. However, Pausanias gives another place called "Museum", namely a small hill in Classical Athens opposite the Akropolis. The hill was called Mouseion after Mousaious, a man who used to sing on the hill and died there of old age and was subsequently buried there as well.
1.1.2. OVERVIEW
Museums collect and care for objects of scientific, artistic, or historical importance and make them available for public viewing through exhibits that may be permanent or temporary. Most large museums are located in major cities throughout the world and more local ones exist in smaller cities, towns and even the countryside. Many museums offer programs and activities for a range of audiences, including adults, children, and families, as well as those for more specific professions. Programs for the public may consist of lectures or tutorials by the museum faculty or field experts, films, musical or dance performances, and technology demonstrations. Many times, museums concentrate on the host region's culture. Although most museums do not allow physical contact with the associated artifacts, there are some that are interactive and encourage a more hands-on approach. Modern trends in museology have broadened the range of subject matter and introduced many interactive exhibits, which give the public the opportunity to make choices and engage in activities that may vary the experience from person to person. With the advent of the internet, there are growing numbers of virtual exhibits, i.e. web versions of exhibits showing images and playing recorded sound.
Museums are usually open to the general public, sometimes charging an admission fee. Some museums are publicly funded and have free entrance, either permanently or on special days, e.g. once per week or year.
Museums are usually not run for the purpose of making a profit, unlike private galleries which more often engage in the sale of objects. There are governmental museums, non-governmental or non-profit museums, and privately owned or family museums. Museums can be a great source of information about cultures and history.
1.2. TYPESOF MUSEUMS
The Pera Museum in Istanbul. The British Museum, in London.
There are many types of museums, from very large collections in major cities, covering many of the categories below, to very small museums covering either a particular location in a general way, or a particular subject, such an individual notable person. Categories include: fine arts, applied arts, craft, archaeology, anthropology and ethnology, history, cultural history, military history, science, technology, children's museums, natural history, numismatics, botanical and zoological gardens and philately. Within these categories many museums specialize further, e.g. museums of modern art, local history, aviation history, agriculture or geology. A museum normally houses a core collection of important selected objects in its field. Objects are formally accessioned by being registered in the museum's collection with an artifact number and details recorded about their provenance. The persons in charge of the collection and of the exhibits are known as curators.
1.2.1. SCIENCES MUSEUM
Science museums and technology centers revolve around scientific marvels and their history. To explain complicated inventions, a combination of demonstrations, interactive programs and thought-provoking media are used. Some museums may have exhibits on topics such as computers, aviation, railway museums, physics, astronomy, and the animal kingdom. Science museums, in particular, may consist of planetaria, or large theatre usually built around a dome. Museums may have IMAX feature films, which may provide 3-D viewing or higher quality picture. As a result, IMAX content provides a more immersive experience for people of all ages. Also new virtual museums, known as Net Museums, have been appearing. These are usually web sites belonging to real museums and containing photo galleries of items found in those real museums. This is very useful for people far away who wish to see the contents of these museums.
Miami Art Museum in Miami, Florida. São Paulo Museum of Art in São Paulo, Brazil.
A number of different museums exist to demonstrate a variety of topics. Music museums may celebrate the life and work of composers or musicians, such as the Rock and Roll Hall of Fame in Cleveland, Ohio. Other music museums include live music recitals such as the Handel House Museum in London.
Museums targeted for the youth, such as children's museums or toy museums in many parts of the world, often exhibit interactive and educational material on a wide array of topics, for example Museum of Toys and Automata. The Baseball Hall of Fame and Museum is an institution of the sports category. The Corning Museum of Glass is devoted to the art, history, and science of glass. The National Museum of Crime & Punishment explores the science of solving crimes. Museum depicts American social history in miniature. Interpretation centre are modern museums or visitors centre that often use new means of communication with the public.
CHAPTER TWO
2.0BUILDINGS AND ACOUSTICS
2.1SOUND
Sound is a pressure wave, which consists of a compression phase and a rarefaction phase. A noise-cancellation speaker emits a sound wave with the same amplitude and the opposite polarity (in antitheses) to the original sound. The waves combine to form a new wave, in a process called interference, and effectively cancel each other out - an effect which is called phase cancellation. Depending on the circumstances and the method used, the resulting sound wave may be so faint as to be inaudible to human ears.
2.2 NOISE CONTROL
Modern active noise control is achieved through the use of a computer, which analyzes the waveform of the background aural or monaural noise, then generates a polarization reversed waveform to cancel it out by interference. This waveform has identical or directly proportional amplitude to the waveform of the original noise, but its polarity is reversed. This creates the destructive interference that reduces the amplitude of the perceived noise.
For instance, noise-cancellation speaker may be co-located with the sound source to be attenuated. In this case it must have the same audio power level as the source of the unwanted sound. Alternatively, the transducer emitting the cancellation signal may be located at the location where sound attenuation is wanted (e.g. the user's ear). This requires a much lower power level for cancellation but is effective only for a single user. Noise cancellation at other locations is more difficult as the three dimensional wave fronts of the unwanted sound and the cancellation signal could match and create alternating zones of constructive and destructive interference. In small enclosed spaces (e.g. the passenger compartment of a car) such global cancellation can be achieved via multiple speakers and feedback microphones, and measurement of the modal responses of the enclosure.
This method differs from passive noise control methods (soundproofing) in that a powered system is involved, rather than unpowered methods such as insulation, sound-absorbing ceiling tiles or muffler.
The advantages of active noise control methods compared to passive ones are that they are generally:
- More effective at low frequencies.
- Less bulky.
- Able to block noise selectively.
There are four basic principles of noise control:
2.2.1 Sound insulation: prevent the transmission of noise by the introduction of a mass barrier. Common materials have high-density properties such as brick, concrete, metal etc.
2.2.2 Sound absorption: a porous material which acts as a ‘noise sponge’ by converting the sound energy into heat within the material. Common sound absorption materials include open cell foams and fiberglass
2.2.3 Vibration damping: applicable for large vibrating surfaces. The damping mechanism works by extracting the vibration energy from the thin sheet and dissipating it as heat. A common material is sound deadened steel.
2.2.4 Vibration isolation: prevents transmission of vibration energy from a source to a receiver by introducing a flexible element or a physical break. Common vibration isolators are springs, rubber mounts, cork etc.
2.3 ARCHITECURAL ACOUSTICS
Architectural acoustics is the science of controlling sound within buildings. The first application of architectural acoustics was in the design of opera houses and then concert halls. More widely, noise suppression is critical in the design of multi-unit dwellings and business premises that generate significant noise, including music venues like bars. The more mundane design of workplaces has implications for noise health effects. Architectural acoustics includes room acoustics, the design of multi-spaces structures such as; recording and broadcast studios, home theaters, and museum etc.
In architectural acoustics and environmental acoustics, noise control refers to the set of practices employed for noise mitigation. Within architectural acoustics these practices include: interior sound reverberation reduction, inter-room noise transfer mitigation and exterior building skin augmentation. More specific architectural noise control methods include the installation of acoustical gypsum, ceiling tiles, ceiling panels, carpet and draperies. In the field of environmental sound, common noise control practices include: design of noise barriers, development, and enforcement of noise abatement legal codes and urban design.
CHAPTER THREE
3.0 ACOUSTICS ANALYSIS IN MUSEUMS
In museums and libraries every reasonable effort should be made to provide the quiet environment essential for studying or reading or contemplating works of art.
Besides the loudness of a sound and its physical impact and effect, one must consider its quality and also the meaning it has to the people that occupy the space. Air conditioning sound is without information content; visitors to the museum are not supposed to listen to it. Whereas in public buildings in the downtown areas such sound sometimes has the function of masking a continuous barrage of obnoxious sounds, this function becomes irrelevant in the surroundings of the museum. Besides the occasional airplane there is nothing to mask here except perhaps the sounds of visitors. And this is, indeed, what it does, more so in some area than in others.
In most other parts of the museum, the air conditioning continues to rule the space. The sound walls created by the air conditioning enwrap each person in a private space of meaningless sound. This, in turn, creates -- often unconsciously -- feelings of distance and isolation in the individual, not only from the other people but also from the artifacts, and the general museum environment. The experience of the artifacts is one step removed.
The visitor who visits the museum for only half an hour might not be conscious of this at all. However, the museum staff and the guards have become very aware of the presence of the air conditioning sound; they are bothered by the noise in their areas. Psychologically the sound seems louder over time, because there is no getting away from it, no getting out of it. It gives a sense of isolation, of being locked in, in the same way a wall without windows does.
3.1 Materials used in architectural acoustics: Acoustical wall and ceiling panels can be constructed of many different materials and finishes. The ideal acoustical panels are those without a face or finish material that interferes with the acoustical infill or substrate. Fabric covered panels are one way to maximize the acoustical absorption. The finish material is used to cover over the acoustical substrate. Mineral fiber board, or Micore, is a commonly used acoustical substrate. Finish materials often consist of fabric, wood or metal. Fabric can be wrapped around substrates to create what is referred to as a "pre-fabricated panel" if laid onto a wall, and require no modifications. Prefabricated panels are limited to the size of the subas "on-site acoustical wall panels" This is constructed by "framing" the perimeter track into shape, infilling the acoustical substrate and then stretching and tucking the fabric into the perimeter frame system. On-site wall panels can be constructed to work around door frames, baseboard, or any other intrusion. Large panels (generally greater than 50') can be created on walls and ceilings with this method.
3.2 Building skin envelope: This science analyzes noise transmission from building exterior envelope to interior and vice versa. The main noise paths are roofs, eaves, walls, windows, door and penetrations. Sufficient control ensures space functionality and is often required based on building use and local municipal codes. An example would be providing a suitable design for a home which is to be constructed close to a high volume roadway, or under the flight path of a major airport, or of the airport itself.
3.3 Interior space acoustics: This is the science of controlling a room's surfaces based on sound absorbing and reflecting properties. Excessive reverberation time, which can be calculated, can lead to poor speech intelligibility.
Sound reflections create standing waves that produce natural resonances that can be heard as a pleasant sensation or an annoying one. In order to obtain a good audio quality it is used the Oscar Bonello criteria of modal density More information at Room acoustics
Reflective surfaces can be angled and coordinated to provide good coverage of sound for a listener in a concert hall or music recital space. To illustrate this concept consider the difference between a modern large office meeting room or lecture theater and a traditional classroom with all hard surfaces.
Interior building surfaces can be constructed of many different materials and finishes. Ideal acoustical panels are those without a face or finish material that interferes with the acoustical infill or substrate. Fabric covered panels are one way to heighten acoustical absorption. Finish material is used to cover over the acoustical substrate. Mineral fiber board, or Micore, is a commonly used acoustical substrate. Finish materials often consist of fabric, wood or acoustical tile. Fabric can be wrapped around substrates to create what is referred to as a "pre-fabricated panel" and often provides the good noise absorption if laid onto a wall. Prefabricated panels are limited to the size of the substrate ranging from 2'x 4' to 4' x 10'. Fabric retained in a wall-mounted perimeter track system, is referred to as "on-site acoustical wall panels" This is constructed by framing the perimeter track into shape, infilling the acoustical substrate and then stretching and tucking the fabric into the perimeter frame system. On-site wall panels can be constructed to accommodate door frames, baseboard, or any other intrusion. Large panels (generally, greater than 50 square feet) can be created on walls and ceilings with this method. Wood finishes can consist of punched or routed slots and provide a natural look to the interior space, although acoustical absorption may not be great.
There are three ways to improve workplace acoustics and solve workplace sound problems – the ABC’s.
A = Absorb (usually via ceiling tile)
B = Block (via workstation panels, wall placement and workspace layout)
C = Cover-up (via electronic sound masking)
While all three of these are recommended to achieve optimal results, C = Cover-up by increasing background sound produces the most dramatic improvement in speech privacy –– with the least disruption and typically the lowest cost.
3.4 CASE STUDY
3.4.1 THE MUSEUM OF ANTHROPOLOGY -- AN ACOUSTICALLY OPPRESSIVE ENVIRONMENT
The Museum of Anthropology is "situated on the most impressive site on the campus of the University of British Columbia, overlooking the Straight of Georgia and the North Shore mountains." (Frompamphlets informing the visitor about the museum). Could one imagine a more suitable site for a museum that preserves primarily West Coast Indian artifacts and objects? It is a place, although within Vancouver city boundaries that still retains some features typical of British Columbia's West Coast, and is usually quiet enough to let the visitor imagine another time in another culture.
As visitors enter the building and the heavy glass door closes behind them this is easily forgotten. The sound "as of a mighty wind" suddenly dominates the entrance hall: it is the air conditioning rushing through the closed but not air-tight door. As one proceeds further into the museum the tune changes. The attentive listener will perceive a continuous low frequency rumble from the air conditioning system that pervades the whole space. It is a familiar sound, the keynote sound of all new public buildings. In fact, it is so familiar to most of us that we tend to ignore it. Yet it is always there, accompanying us on our journey through the museum, sometimes louder, sometimes less audible. The map below indicates the sound levels in the various areas of the building, both during and after visiting hours.