Exhibit Sound Designfor Public Presentation Spaces
(pub. Museum Management and Curatorship. Vol 13:2 Butterworth-Heinmann June 1994)
In the design of museum exhibits, much thought is given to what the presentation environment looks like. It is not often considered what the environment should sound like.Sound is the "Hidden Dimension" in exhibit design, capable of transporting the visitor into an exhibit's imaginary environment. In speaking about sound, we are not just referring to the fidelity of speakers or the information content of a presentation, rather we are including the integration of sound and noise within the context of an exhibit and it's environment.
There are three basic considerations in the design of exhibit sound; the content of the produced sound for an exhibit, the presentation hardware, including speakers and control systems , and the acoustical setting, or sound environment.
All three of these considerations can compliment each other, and strengths in one area can fill in for weaknesses in other areas to a certain degree, though the acoustical setting is the only element of the three that can stand alone as a presentation tool. And while most of the sound design effort for an exhibit will go toward production of audio material and system design, often the environment in which the sound is presented is overlooked. The importance of this observation will be explored later in this article.
Designing for Sound
In designing any type of exhibit, the first question that must be asked is "What is the intention of the Exhibit?". Once the intention of the exhibit is clearly defined, it must always be used as a benchmark by which all design elements are considered, bearing in mind that the measure of the lasting impact of an exhibit lies in how effectively the exhibit pulls the visitor into the presentation.
Though sound may not be a key element in an exhibit presentation, for most exhibit visitors, sound (or noise) will always be present in an exhibition space and as such should be considered to some degree as a part of all designs. If sound is not a presentation element, it should be determined weather the environment will be too noisy to concentrate on written material, or if the environment will be too quiet to allow the visitor to be comfortable using the exhibit and share their experiences with others in the exhibit.
If sound is an exhibit element, is the quality of the sound easy to listen to, or does the sound presentation conflict with other perceptual cues of the exhibit? Is the amount of spoken information too cumbersome to easily convey the intent of the exhibit, and does the sound presentation capture the listener and not just add to the overall noise level in the exhibit environment?
These are just some of the questions that an exhibit designer needs to consider about sound even before the actual sound element or acoustical environment is designed.
Sound Production ContentSound production falls within three basic categories; narrative, music, and ambiance. These categories directly correspond to the "voice, music and sound effects" categories used in movie sound production. All three categories may contain information, all may work together and all can stand alone. In fact sound production can either be used as an enhancement to a visual or tactile exhibit, or act as a complete presentation in itself.
Narrative production can be in the form of a scripted information piece read by a voice actor, or as "oral histories" and stories recorded from the accounts and tales of people whose experience supports or is the subject of the exhibit.
Care must be taken especially in the production of scripted information pieces that the piece doesn't become too complex or try to deliver too much information. A narrative piece that is too heavily "loaded" will give the listener the feeling of being lectured or spoken at. Often some of the risk of this can be ameliorated by using music or ambiance to buffer the spoken script as well as carry some of the information.
"Oral histories" and stories can have the advantage of carrying subconscious information without the "list of facts" feel that a scripted production may have, though "oral histories" can run the risk of being too "wordy". Careful editing of oral histories may be required to clearly present the point of the piece while retaining the significance of the narrative.
On advantage of recording "oral histories" for a presentation is that this material actually becomes a part of the exhibitors "collection" in terms of it being unique and valuable information. Cataloged properly, it can be archived and used for research and education to further the intent of the original exhibit.
Which ever form of narrative used, keeping the presentation sounding natural and un-forced will go a long way in keeping the attention of the listeners. A "corny" delivery or a bad voice actor can easily undermine the credibility an exhibit regardless of how compelling the story or script is.
Although all sound will have some emotional impact on a sub-conscious and conscious level, music can most directly affect the mood of the listener. Even music used in a strictly documentary manner, such as in historical "musical examples" will affect the listeners emotional disposition.
Music can be a direct element of an exhibit or presentation, as an accompaniment to visual and motion elements, or used as an ambiance to set the mood of a piece. Ambient music can be also be used to thematically tie exhibit areas together, or to highlight specific areas or topics within an exhibit.
The decision to use pre-recorded or pre-published music as opposed to unique music composed for the presentation will be determined by a number of factors, including event synchronization, historic content, availability of appropriate material and cost. It should not be assumed that original music will be more costly than pre-published material. The cost will be dependent on many variables such as exclusivity, repackaging for sales, and the variety of material needed. Use of the exhibit music to sell as a "CD" or cassette from a museum store could significantly shift the composers' or publishers' license priorities for example.
Regardless of what the source of the music is, it is important the performance rights are secured. If the music is original and composed for the presentation, the composer may have a performance license agreement or ownership clause in their contract. Music that has been previously published needs to be cleared for use, even if it is performed specifically for the presentation. This requires that and agreement be made with the publisher. If the publisher is not known, rights can be arranged through one of the two musical performance rights societies, ASCAP - American Society of Composers and Producers or BMI - Broadcast Music Inc.
Perhaps the strongest impact of all sound presentation techniques can be derived from the creation of an ambient sound environments. An ambient environment can transport the imagination through time and space, allowing the listeners to visit tropical rain forests, 19th.Ęcentury train stations, Arctic tundra or aboriginal villages without moving. A static visual exhibit which would otherwise be viewed by a visitor in passing will be stared at in detail if it is enhanced with a complimentary ambient sound environment.
Sound environments can be custom tailored to an exhibit, with sound cues keyed into other exhibit elements, or sounds and environments can be resourced from existing productions and libraries. As is the case with music, pre-recorded and produced ambient environments and sound effects need to be licensed and cleared for use. A sound resource library will generally have a stock sound use agreement, as will the producer for custom sound ambients.
If custom sound is recorded for the presentation, clear ownership rights should be established with the recordist and producer. If the exhibitor retains ownership of recorded material, it can become part of the exhibitors "collection", available for research and re-use in other settings. The disposition of the ownership will have some impact on the cost of custom recorded sound.
Presentation Equipment and Techniques
With the availability of new and exciting presentation technologies it is easy to get distracted from the intent of an exhibit design and allow the technologies to drive the presentation. It is during the equipment selection, perhaps more than at any other stage of the sound design where the question of the intent of the exhibit must always be asked. This is due in part to fact that the dazzling quality of much of the available equipment can easily become a distraction in the design process. It is also true that unlike sound designers, equipment vendors have an interest in selling equipment which is not directly tied to the effectiveness of the sound presentation.
Sound presentation technologies currently employed in an exhibit can range in complexity (and expense) from a simple speaker on a repeating sound "loop" to a complex interactive audio "database" that calls up specific localized sound sources on a cue selected by a visitor on a video touch screen. There are so many possibilities in presentation technologies that there are many trade publications dedicated to their promotion and understanding. Suffice it to say that it is beyond the scope of this article to enumerate the possibilities.
When considering what equipment to use, durability must be thoroughly evaluated. This is true of all materials used in public spaces, but especially true of technical gear due to the higher cost of qualified maintenance personnel, and the high cost of replacing failed technical gear. In the assessment of equipment use, it is not extraordinary to take the anticipated public traffic for an exhibit and triple it, using this as a benchmark for establishing a technical maintenance budget. Remember, buttons will get pressed, keyboards will get mashed, headphone cables will get yanked and monitors will get hit, over and over again, and the abuse of these things will be directly proportional to how exciting and compelling the presentation is.
Safety is another consideration that should never be overlooked. All sound technologies use electricity and power, and although the audio and control voltages exposed to the public are generally low, and pose no threat of electrical shock, heat and sparks could be generated, causing a risk of fire. Make sure that all technical installation procedures adhere to local and national electrical, fire and building codes.
It is equally important to confirm that audio volume levels in a presentation do not exceed levels that are potentially damaging to the visitor or the exhibition staff. O.S.H.A - the U.S. Occupational Safety and Health Administration has established guidelines for safe short term and long term sound and noise exposure. Other countries have equivalent governing agencies and standards. These guidelines should be used as an upper limit for sound and noise levels, as they are designed for work environments, not education and leisure environments.
Digital technology has become an incredible boon for technical presentation systems. It has allowed the designer much more flexibility through computer control, and greater reliability through the characteristic use of less moving parts than what was afforded by older analog technologies. Digital technology standards have also come to a level of maturity that there is some room for growth and "updates", as well as cross compatibility between manufacturers to ameliorate the concern for immediate obsolescence once a system is installed.
With all of the sound sources and control systems available, there is still a common factor to all sound system designs - speakers. Speakers are also potentially the weakest link because it is almost axiomatic that the larger the speaker, the better the fidelity and the more believable the sound, and the success of an audio presentation, though dependent on content, can be made or broken by the believability of the sound. Unfortunately, not many exhibits can cater to the visual presentation of large speaker enclosures, so many tricks must be employed either to decrease the size of the enclosure or to conceal the enclosures in other exhibit elements.
With the exception of headphones and monophonic "talking boxes", it is also important to try to maintain a "sound field" in an exhibit space. This is often in conflict with concealing speakers in an exhibit, or assuring that the sound field doesn't bleed into and distract focus from adjacent exhibit spaces. There are often many opportunities for compromise when placing speakers in an exhibit space.
A "talking box" in an exhibit hall is just that, an information kiosk or video monitor with a sound source delivering narrative. Regardless of how compelling the information is, a visitor will be easily distracted from this type of presentation unless the "talking box" is isolated from other interesting sensations in the museum. It is a complete stand alone exhibit and should be placed in a corner or near benches so that it can serve as a rest stop as well as a presentation.
The Acoustical Setting
Undoubtedly the most neglected aspects of exhibit design are the acoustical considerations. It is a well known, but often overlooked fact that an acoustical environment affects the behavior of the people within the environment. People tend make noise in reverberant environments, honking horns in tunnels or whistling in large gymnasiums for example. Conversely, people tend to speak quietly in acoustically "dampened" environments, such as thickly carpeted offices, coat closets or libraries.
Though traditional concerns of high speech intelligibility, low ambient noise levels and good space isolation are common acoustical design objectives in exhibition spaces, the affects of "psycho-acoustics" can play a strong role in the suspension of belief and the overall impact of an exhibit experience.
"Psycho-acoustics" in space design refers to the psychological effect that the acoustics of a space has on the visitor. Although people get strong direct visual cues from their immediate environment, providing them with an empirical view of the space they are in, acoustics, like smell and peripheral vision, will set the subconscious cues to give the visitor a sense of where they are. These cues, when carefully designed, can help compel the visitor to move, to rest, to feel vulnerable and exposed, or to feel safe and contained.
In public space design, psycho-acoustic design can be used to encourage traffic flow or create "waiting areas", but more importantly, by creating acoustical spaces that may contradict, or are appropriately juxtaposed to the visitors visual experience, windows of perception are opened, allowing the experience to permeate into the subconscious.
Due to the strength of this effect, acoustical design can play an important role in exhibit sound productions. It can also play an important role in setting the impact of an exhibition facility on the visitor even without the use of sound elements in the design.
An example of a totally integrated Aural Environment might be to acoustically dampen the presentation space to induce the visitors to be quiet and become submerged in an aural "Space Sculpture". This strategy might be very effective in the presentation of pristine natural environments such as a Desert Savannah, a Tropical Rain Forest, or a Deep Water Aquarium.
In another environment, it might be appropriate to integrate the sounds of the visitors by masking and blending in the acoustical treatments to cloud the distinction between the visitors and the exhibit. This strategy could be used in a historical presentation where acoustically placing the visitor in the social context of the exhibit theme would increase their sense of "being there", enhancing the impact of the event. This technique might be used in a "period" replica scene, such as a Western Frontier Town, or a Warsaw Ghetto.
If acoustical techniques are employed to enhance a presentation, a thorough discussion about the intention of the exhibit environment should take place between the Architect, the Exhibit Designer and the Acoustical Designer. Though this discussion would naturally include considerations for sound presentation and anticipated noise levels from the visitor traffic and mechanically generated noise, it may also include considerations of the impact that the space should have on the visitors sense of placement. Questions might include weather the space should be designed to induce comfortable conversation, or to keep the visitors quiet, or weather the space should keep the visitors moving through it, or be a "de-compression" area to allow the visitor to collect their thoughts.
Regardless of how sophisticated the acoustical design requirements are, an Acoustical Engineer should be consulted at the beginning of an exhibit space design. This will insure that noise generated by HVAC and other mechanical equipment doesn't compromise the sound environment in the exhibit spaces. An Acoustical Engineer can also insure that the acoustical treatments are consistent with the finish shapes and materials that the Exhibit Designer or Building Architects are using, and that acoustical treatments don't compromise or interfere with building life/safety equipment. In more sophisticated exhibit settings, an Acoustical Designer should be consulted to insure that the impact of the exhibit is enhanced by it's aural environment.
Exhibit design is predominantly approached on a visual level, but regardless of how visually compelling an exhibit is, if it is not accompanied by a complimentary audio presentation or sound environment, the exhibit can easily fall "flat".
In developing audio enhancements to an exhibit, the objective is to clearly and accurately convey the intention of that exhibit. Though narrative presentation is an affective method to deliver information to an exhibit visitor, music, ambient sound and acoustics can play a strong role in developing the impact of an exhibit. Presentation subtlety can also assist in the suspension of belief necessary for exhibit to reach the visitor on a subconscious level.
With the ever increasing sophistication of home entertainment systems available to the general public, it is becoming imperative that Public Exhibit Presenters provide total experiences that would be otherwise unavailable to their audiences. This includes the expansion and integration of "Spectacle" onto the full space available to the presentation, appealing to all of the senses and suspending the temporal and spatial belief of the visitors.
Considering Sound Design at an early stage of Exhibit Planning can contribute substantially to these goals.
1994 Michael Stocker
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