Sonification is the use of non-speech audio to convey information or perceptualize data. [1] Auditory perception has advantages in temporal, spatial, amplitude, and frequency resolution that open possibilities as an alternative or complement to visualization techniques.
For example, the rate of clicking of a Geiger counter conveys the level of radiation in the immediate vicinity of the device.
Though many experiments with data sonification have been explored in forums such as the International Community for Auditory Display (ICAD), sonification faces many challenges to widespread use for presenting and analyzing data. For example, studies show it is difficult, but essential, to provide adequate context for interpreting sonifications of data. [1] [2] Many sonification attempts are coded from scratch due to the lack of flexible tooling for sonification research and data exploration. [3]
The Geiger counter, invented in 1908, is one of the earliest and most successful applications of sonification. A Geiger counter has a tube of low-pressure gas; each particle detected produces a pulse of current when it ionizes the gas, producing an audio click. The original version was only capable of detecting alpha particles. In 1928, Geiger and Walther Müller (a PhD student of Geiger) improved the counter so that it could detect more types of ionizing radiation.
In 1913, Dr. Edmund Fournier d'Albe of University of Birmingham invented the optophone, which used selenium photosensors to detect black print and convert it into an audible output. [4] A blind reader could hold a book up to the device and hold an apparatus to the area she wanted to read. The optophone played a set group of notes: g c' d' e' g' b' c e. Each note corresponded with a position on the optophone's reading area, and that note was silenced if black ink was sensed. Thus, the missing notes indicated the positions where black ink was on the page and could be used to read.
Pollack and Ficks published the first perceptual experiments on the transmission of information via auditory display in 1954. [5] They experimented with combining sound dimensions such as timing, frequency, loudness, duration, and spatialization and found that they could get subjects to register changes in multiple dimensions at once. These experiments did not get into much more detail than that, since each dimension had only two possible values.
In 1970, Nonesuch Records released a new electronic music composition by the American composer Charles Dodge, "The Earth's Magnetic Field." It was produced at the Columbia-Princeton Electronic Music Center. As the title suggests, the composition's electronic sounds were synthesized from data from the earth's magnetic field. As such, it may well be the first sonification of scientific data for artistic, rather than scientific, purposes. [6]
John M. Chambers, Max Mathews, and F.R. Moore at Bell Laboratories did the earliest work on auditory graphing in their "Auditory Data Inspection" technical memorandum in 1974. [7] They augmented a scatterplot using sounds that varied along frequency, spectral content, and amplitude modulation dimensions to use in classification. They did not do any formal assessment of the effectiveness of these experiments. [8]
In 1976, philosopher of technology, Don Ihde, wrote, "Just as science seems to produce an infinite set of visual images for virtually all of its phenomena--atoms to galaxies are familiar to us from coffee table books to science magazines; so 'musics,' too, could be produced from the same data that produces visualizations." [9] This appears to be one of the earliest references to sonification as a creative practice.
In early 1982 Sara Bly of the University of California, Davis, released two publications - with examples - of her work on the use of computer-generated sound to present data. At the time, the field of scientific visualization was gaining momentum. Among other things, her studies and the accompanying examples compared the properties between visual and aural presentation, demonstrating that "Sound offers and enhancement and an alternative to graphic tools." Her work provides early experiment-based data to help inform matching appropriate data representation to type and purpose. [10] [11]
Also in the 1980s, pulse oximeters came into widespread use. Pulse oximeters can sonify oxygen concentration of blood by emitting higher pitches for higher concentrations. However, in practice this particular feature of pulse oximeters may not be widely utilized by medical professionals because of the risk of too many audio stimuli in medical environments. [12]
In 1992, the International Community for Auditory Display (ICAD) was founded by Gregory Kramer as a forum for research on auditory display which includes data sonification. ICAD has since become a home for researchers from many different disciplines interested in the use of sound to convey information through its conference and peer-reviewed proceedings. [13]
In May 2022, NASA reported the sonification (converting astronomical data associated with pressure waves into sound) of the black hole at the center of the Perseus galaxy cluster. [14] [15]
Many different components can be altered to change the user's perception of the sound, and in turn, their perception of the underlying information being portrayed. Often, an increase or decrease in some level in this information is indicated by an increase or decrease in pitch, amplitude or tempo, but could also be indicated by varying other less commonly used components. For example, a stock market price could be portrayed by rising pitch as the stock price rose, and lowering pitch as it fell. To allow the user to determine that more than one stock was being portrayed, different timbres or brightnesses might be used for the different stocks, or they may be played to the user from different points in space, for example, through different sides of their headphones.
Many studies have been undertaken to try to find the best techniques for various types of information to be presented, and as yet, no conclusive set of techniques to be used has been formulated. As the area of sonification is still considered to be in its infancy, current studies are working towards determining the best set of sound components to vary in different situations.
Several different techniques for auditory rendering of data can be categorized:
An alternative approach to traditional sonification is "sonification by replacement", for example Pulsed Melodic Affective Processing (PMAP). [52] [53] [54] In PMAP rather than sonifying a data stream, the computational protocol is musical data itself, for example MIDI. The data stream represents a non-musical state: in PMAP an affective state. Calculations can then be done directly on the musical data, and the results can be listened to with the minimum of translation.
A Geiger counter is an electronic instrument used for detecting and measuring ionizing radiation. It is widely used in applications such as radiation dosimetry, radiological protection, experimental physics and the nuclear industry.
The Bark scale is a psychoacoustical scale proposed by Eberhard Zwicker in 1961. It is named after Heinrich Barkhausen, who proposed the first subjective measurements of loudness. One definition of the term is "a frequency scale on which equal distances correspond with perceptually equal distances. Above about 500 Hz this scale is more or less equal to a logarithmic frequency axis. Below 500 Hz the Bark scale becomes more and more linear."
Maryanne Amacher was an American composer and installation artist. She is known for working extensively with a family of psychoacoustic phenomena called auditory distortion products, in which the ears themselves produce audible sound.
In acoustics, loudness is the subjective perception of sound pressure. More formally, it is defined as the "attribute of auditory sensation in terms of which sounds can be ordered on a scale extending from quiet to loud". The relation of physical attributes of sound to perceived loudness consists of physical, physiological and psychological components. The study of apparent loudness is included in the topic of psychoacoustics and employs methods of psychophysics.
Auditory phonetics is the branch of phonetics concerned with the hearing of speech sounds and with speech perception. It thus entails the study of the relationships between speech stimuli and a listener's responses to such stimuli as mediated by mechanisms of the peripheral and central auditory systems, including certain areas of the brain. It is said to compose one of the three main branches of phonetics along with acoustic and articulatory phonetics, though with overlapping methods and questions.
Sensory substitution is a change of the characteristics of one sensory modality into stimuli of another sensory modality.
Auditory display is the use of sound to communicate information from a computer to the user. The primary forum for exploring these techniques is the International Community for Auditory Display (ICAD), which was founded by Gregory Kramer in 1992 as a forum for research in the field.
In physics, sound is a vibration that propagates as an acoustic wave through a transmission medium such as a gas, liquid or solid. In human physiology and psychology, sound is the reception of such waves and their perception by the brain. Only acoustic waves that have frequencies lying between about 20 Hz and 20 kHz, the audio frequency range, elicit an auditory percept in humans. In air at atmospheric pressure, these represent sound waves with wavelengths of 17 meters (56 ft) to 1.7 centimeters (0.67 in). Sound waves above 20 kHz are known as ultrasound and are not audible to humans. Sound waves below 20 Hz are known as infrasound. Different animal species have varying hearing ranges.
David Worrall is an Australian composer and sound artist working a range of genres, including data sonification, sound sculpture and immersive polymedia as well as traditional instrumental music composition.
In signal processing, sub-band coding (SBC) is any form of transform coding that breaks a signal into a number of different frequency bands, typically by using a fast Fourier transform, and encodes each one independently. This decomposition is often the first step in data compression for audio and video signals.
Psychoacoustics is the branch of psychophysics involving the scientific study of the perception of sound by the human auditory system. It is the branch of science studying the psychological responses associated with sound including noise, speech, and music. Psychoacoustics is an interdisciplinary field including psychology, acoustics, electronic engineering, physics, biology, physiology, and computer science.
Sonic interaction design is the study and exploitation of sound as one of the principal channels conveying information, meaning, and aesthetic/emotional qualities in interactive contexts. Sonic interaction design is at the intersection of interaction design and sound and music computing. If interaction design is about designing objects people interact with, and such interactions are facilitated by computational means, in sonic interaction design, sound is mediating interaction either as a display of processes or as an input medium.
Sound and music computing (SMC) is a research field that studies the whole sound and music communication chain from a multidisciplinary point of view. By combining scientific, technological and artistic methodologies it aims at understanding, modeling and generating sound and music through computational approaches.
The International Community for Auditory Display (ICAD), founded in 1992, provides an annual conference for research in auditory display, the use of sound to display information. Research and implementation of sonification, audification, earcons and speech synthesis are central interests of the ICAD.
Audification is an auditory display technique for representing a sequence of data values as sound. By definition, it is described as a "direct translation of a data waveform to the audible domain." Audification interprets a data sequence and usually a time series, as an audio waveform where input data are mapped to sound pressure levels. Various signal processing techniques are used to assess data features. The technique allows the listener to hear periodic components as frequencies. Audification typically requires large data sets with periodic components.
3D sound is most commonly defined as the daily human experience of sounds. The sounds arrive to the ears from every direction and varying distances, which contribute to the three-dimensional aural image humans hear. Scientists and engineers who work with 3D sound work to accurately synthesise the complexity of real-world sounds.
Wanda Díaz-Merced is a Puerto Rican astronomer known for using sonification to turn large data sets into audible sound. Currently at the European Gravitational Observatory Cascina, Italy, Wanda is the Director of the Arecibo Observatory. While losing her eyesight, Wanda brought attention to increasing equality of access to astronomy and using audible sound to study astrophysical data.. Wanda is a part of the 7 most trailblazing women in science by the BBC.
Apparent source width (ASW) is the audible impression of a spatially extended sound source. This psychoacoustic impression results from the sound radiation characteristics of the source and the properties of the acoustic space into which it is radiating. Wide source widths are desired by listeners of music because these are associated with the sound of acoustic music, opera, classical music, and historically informed performance. Research concerning ASW comes from the field of room acoustics, architectural acoustics and auralization, as well as musical acoustics, psychoacoustics and systematic musicology.
Data sonification is the presentation of data as sound using sonification. It is the auditory equivalent of the more established practice of data visualization.
Gregory Paul Kramer, is an American composer, researcher, inventor, meditation teacher and author. In 1975 he co-founded Electronic Musicmobile, a pioneer synthesizer ensemble later renamed Electronic Art Ensemble, in which Kramer was a musician and composer. His pioneering work extended to developing synthesizer and related equipment. Kramer also co-founded the not-for-profit arts organization Harvestworks in New York City. He is recognized as the founding figure of the intensely cross-disciplinary field of data sonification. Since 1980, Kramer teaches Buddhist meditation. He is credited as developer of Insight Dialogue, an interpersonal meditation practice. Kramer is the author of several books in diverse fields, as well as (co-)author of scientific papers in the field of data sonification.