A sound installation is an intermedia and time-based art form. Intermedia = art practices that occur between different art genres. For example—drawing + poetry = visual poetry and painting + theater = performance art. This is an expansion on the concept of art installation in that sound introduces the concept of time necessary for listening to the work(s) featured in the installation.
How is "sound installation" different from "art installation"?
The difference between a sound installation and an art installation is that a sound installation includes the time element, which can invite the visitor to stay longer and see how the sound element will unfold over time.
Specifically, a sound installation makes a dialog with the surrounding three dimensional space. Usually, sound installations are site specific, but can be adapted for other, different spaces. The time of the sound encourages visitors to explore the space in which the sound(s) occur, discover their dispositions.
Sound installations can use interactive technologies (computers, sensors, mechanical, and kinetic devices). The sound source is usually speakers, but acoustic music instruments / materials that can be played by visitors can also be used.
The name we give to our physical subjective experience of acoustic energy. Sound originates from some source, and moves in all directions as a sequence of pressure variations (waves) from that source and travels through some medium (air, gas, water). If these oscillations are within the range of human hearing (20hz-20Khz) they are "heard" when they reach our ears. See "Resources," below, for more.
A means of capturing, processing, storing, and reproducing sound through an electronic medium. Two kinds of recording: analog and digital. Analog recording uses mechanical devices to convert changing air pressure (sound waves) into changing electrical signals which can be recorded and preserved. On playback, these changing electrical signals cause a speaker cone to vibrate, creating sound waves that match the original source. We "hear" these sound waves. Called "analog" because the signal information is represented by continuously changing quantity of electrical voltage. Digital recording uses discrete binary time and amplitude signals, rather than continuously changing electrical signals, to record and playback sounds. These discrete digital signals (samples) can be corrected, and manipulated later. This is the key to reconstitution of the original sound, and correction of any errors. Digital samples are not susceptible to distortion due to inherent noise in electrical circuits of analog recording systems. See "Resources," below, for more.
Sculpture or any kind of art object that produces sound(s)
Is intermedia and time based art form
Sometimes is site specific. See "Resources," below, for more.
Example Sound Installations
Sound installations are, for Manuel Rocha Iturbide, works incorporating different media, including sound, which, when combined, expand traditional concepts of sculpture and installation. The results could include a new, temporal perception of the space surrounding the installation, heightened awareness of the characteristics of the place of the installation, and a heightened awareness of sound. We do not, he says, need visual elements. A sound installation can be structured with only sound (Iturbide, 2014). Some examples follow.
16 June-28 August 2006, Millenium Bridge and Tate Modern, London
American sound artist Bill Fontana (1947- ) used accelerometers to translate into sound the vibrations within the London Millenium Bridge caused by footsteps, load, and wind. In essence, the bridge was turned into a musical instrument spanning the Thames River in London. Fontana recorded these normally imperceptible vibrations and their changes as sound processes and amplified them through an array of speakers in the Turbine Hall of the Tate Modern, located at the southern end of this pedestrian footbridge, and another located in the Southwark Underground station. Both sound installations were continuously modified by responses from the bridge's structure. The bridge, as a sound sculpture, was a source of musical information, constantly changing in response to people walking on the bridge, the vertical load they placed on the bridge, along with the lateral load of any wind along the river. The intent was to provide a sonic rereading of the bridge, as well as a reconceptualization of its experience as people walked across its span from Bankside to London City. "Harmonic Bridge" is one of several international site-specific sound installations where Fontana uses sounds as a sculptural medium to interact with and transform our perceptions of visual and architectural settings.
Playing the Building
2005-2012, various locations
Remember The Talking Heads? David Byrne was one of leaders behind their greatness and he continues on the cutting edge with a series of sound installations in buildings where the building itself is used as a musical instrument, much like Fontana's use of the London Millenium Bridge. Devices are placed on the building's structure components and then used to make the building vibrate, resonate, oscillate. The devices do not produce sounds themselves, but rather cause the building itself to produce wind, vibration, or striking sounds. The audience can "play" the building through an organ keyboard. In this sample, recorded in October 2005 by Emma Karlsson, at the Färgfabriken installation, Stockholm, Sweden, 8 October - 13 November 2005, visitors play the building.
Resources > Byrne
David Byrne: Playing the Building at YouTube website.
12 May 2005 - November 2006, Eastern State Penitentiary, Philadelphia, Pennsylvania
Canadian sound artists Janet Cardiff and George Bures Miller used the two-story Cellblock Seven as a percussive instrument for this site-specific sound work. They installed one hundred and twenty six beaters on toilet bowls, light fixtures, and bedside tables throughout the cell block, all controlled by a computer and midi system. The fifteen-minute composition begins subtly, as if two prisoners are trying to communicate and then moves through an abstract soundscape and lively dance beats to a riot-like crescendo. Eastern State Penitentiary, begun in 1821, once the most expensive and famous prison in the world (Al Capone was imprisoned in a vaulted, sky-lit cell here) is now in ruins but still a prominent landmark in downtown Philadelphia.
British sculptor and video artist Darren Almond's HMP Pentonville (1997) also combines an empty prison site and sound generated there. Almond used a video camera inside an empty cell at Her Majesty's Prison at Pentonville, North of London, and relayed the signal via satellite to the Institute of Contemporary Art, London, where it was projected live, larger than life during the opening reception, 7 May, for two hours and then looped as a recording for the remainder of the exhibition. Nothing happens in the video. All the action is in the audio outside the cell, the unending din of voices, keys grating in locks, metal doors banging, and announcements from speakers echoing off the hard surfaces. As a result, the sound is perhaps the most remembered aspect of Almond's work.
1977 - present, Times Square, New York
American percussionist and sound artist Max Neuhaus (1939-2009) coined the terms "sound work" and "sound installation," and produced a number of site specific sound installations in Europe (Duckworth, 1994, 42-49). "Times Square" is his only surviving sound installation in the United States. Located on Broadway, between 45th and 46th Streets, in New York's Time Square, in a traffic median covered largely by mesh metal grates, the work uses the existing architecture of a subway ventillation system to amplify and resonate tones produced by a synthesizer in a tunnel below the grates. The work ran nearly continuously from 1977-1992, and from 2002 to present. Unmarked, dependent on discovery, "Times Square" can still be heard, 24/7. A new drama is created with each listener. 
The Forty-Part Motet
2001, various locations
A reworking of the choral composition "Spem in Alium" by Thomas Tallis (1573). Forty separately recorded voices are played back through forty speakers strategically placed throughout the space. Although not specific to one location, this work does utilize its location for acoustic specificity.
Resources > Cardiff
Janet Cardiff's website.
12 October 2004-2 May 2005, Tate Modern, London
American artist Bruce Nauman (1941- ) was commissioned to produce a sound installation for the cavernous Turbine Hall in the Tate Modern, London, England. His work, "Raw Materials," used twenty two spoken word fragments from previous works to create a single sound collage that took on new meaning as it was heard throughout the space in conjunction with the changing sounds of visitors. "Raw Materials" reflects Nauman's interest in human language and how it is used to communicate, or not. Removed from their original contexts, these speech fragments take on new, abstract meanings as part of this work. Nauman placed speakers on opposite sides of the Turbine Room, creating bands of sounds through which visitors walked as they traversed the room in either direction. As a result, the sound fragments, along with the "found sounds" of visitors, become sculptural material, ambient sound swirling throughout the Turbine Hall, shaping and orchestrating the space into a metaphor for the world of language, echoing endlessly with jokes, poems, pleas, greetings, statements, and propositions. The arrangement of the pieces was, from east to west entrances, as follows
1. Thank You Thank You
2. You May Not Want To Be Here
3. Work Work
4. Pete and Repeat / It was a Dark and Stormy Night
5, 6. No No No No—New Museum / Walter
7. 100 Live and Die
8. False Silence
9. OK OK OK
10. Think Think Think
11. Amazing Luminous Fountain
12. Get Out of My Mind, Get Out of This Room
13. Left or Standing / Standing or Left Standing
14. Consummate Mask of Rock
15. Anthro / Socio
16, 17. Good Boy Bad Boy—Tucker / Joan
18. Shit In Your Hat—Head On A Chair
19, 20. World Peace—Bernard / mei mei
21. Raw Material—MMMM
Here is a sample from Nauman's installation. Imagine yourself walking through a space the size of an airplane hanger.
Resources > Nauman
Bruce Nauman—Raw Materials is an interactive recreation of Nauman's sound installation; simulates the experience of walking up and down the Turbine Hall hearing the various speech fragments.
Bruce Nauman—Raw Materials: Tate Modern 2005 YouTube video from which the sound sample above was taken.
The Unilver Series: Bruce Nauman: Raw Materials at the Tate Modern website.
Music for 18 Machines—Show preview
Reimagines Music for 18 Musicians by Steve Reich for performance by 18 synstheziers.
Barber, John. Sounds of My Life: A Sixties Radio Narrative
Barber, John. Sound Diary
Barber. John. Sonic Miniatures
The Conet Project on the Soundcloud website
The Conet Project on the Internet Archive website
Medoff, Liz and Andy Slater. There Is No Discrete
Wynne, John. 300 Speakers, Pianola and Vacuum Cleaner. 23 May 2014.
An installation by sound artist John Wynne.
A Room Listening to Itself
Adam Basanta, 2015
Sounds of Wikipedia edits
This sonification of information plays a different sound each time someone edits a Wikipedia document. Sound depends on type of edit, and amount of text edited. NOTE: apparently no longer available. Moved to or replace by Project Audio at GitHub, see below.
Project Audio at GitHub
A real time sonification of edits made to GitHub. Like the Wikipedia project, a different sound, depending on the size of the edit, is made each time someone edits content on the GitHub website.
Listeners were invited to call the nearest of five National Public Radio stations around the county. They whistled a continuous tone into the telephone until disconected by the Neuhaus-built answering system. The sounds were mixed and looped through all five radio stations and then to Washington, DC, where it was broadcast across the NPR network for two hours, 2 January 1977. Learn more and listen.
Online Transnational Radio Experience exhibition, developed by the Netherlands Institute for Sound and Vision and Studio Moniker. The Google of Earth's radio stations. Spin the globe and listen to current and historical radio broadcasts around the world, as well as stories and jingles. Learn more and listen.
The Harbour Symphony
An annual event at the St. John's International Sound Symposium. Features original compositions for the homs of ships in the St. John's harbor, St. John's, Newfoundland, Canada. The sound reverberates off the surrounding hills and through the streets of St. John's. Learn more and listen.
Cage, John. Water Walk
John Cage, the greatest experimental music composer of the twentieth century, performs his Water Music on the I've Got A Secret television game show, January 1960.
Céleste Boursier-Mougenot: clinamen
More than one hundred white porcelain bowls float around a blue pool of water. A they collide as precussive instruments, they create a chiming soundscape. A chance-driven performance event.
Sound Art, Creative Installations
Forty one (41) sound art, creative installations documented in video. Watch, listen, and learn.
Kramer, Mike. Mike Sound Art Installation "Whispering Wall III" at SCHUNCK
Contact microphones listen to sounds in walls that we normally don't hear, or pay attention to. Headphone listening recommended.
This experiment in artificial intelligence not only visualizes the waveforms for North American bird songs, but also groups each with the next closest example. Developed using Google open source code.
Sonic Memorial Project, The
Begun shortly after the 11 September 2011 destruction of the World Trade Center in New York, the Sonic Memorial was opened as a site for people to share their stories and recordings of life events associated with the twin towers. Today, this archive and online audio installation of personal and historic sonic traces, artifacts, interviews, and oral histories is valuable to family, friends, historians, archivists, and producers.
12 Sound Artists Changing Your Perception of Art
These twelve sound artists are expanding the way we engage with sound art, whether it is performance, installation, analogue machines, custom instruments, field recordings, or something else.
The View from the Shard
From the observation deck of The Shard, sixty-eight stories above the street, you have a pretty incredible 360-degree panorama of London, England. This website allows you to interact with that view, bringing up points of historical and cultural interest, as well as listening to a continuous soundscape. Note, for example, how the sound(s) change as you zoom in or out of distant views or sounds.
Episode 97, 99% Invisible
A podcast about an art installation about radio stations that transmit only numbers. If you like this idea for a sound installation, see Shortwaveology website for more information.
Iturbide, Manuel Rocha. The Sound Installation.
An unpublished academic paper by Manuel Rocha Iturbide in which he explains and details what is meant by sound installation. Useful for the theoretical overview. Available as .PDF download here
Seiffarth, Carsten. About Sound Installation Art. Kunstjournalen B-post, 2012.
Open Sound & Sound Thinking
An annual exhibition of sound installations at the Surrey (Canada) Art Gallery
Reverb: The Evolution of Architectural Acoustics
Episode #236 of 99% Invisible
The Birth of Loop by Michael Peters
Artist Talks From the 20th Century
Artist lectures from the 1960s-1990s available at the Maryland Institute College of Art Decker Library.
Curated by Mark Amerika. A collection of websites using sound in unusual, creative, even provocative ways.