Acousmetry® - The visibile sound

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Acousmetry, from gr. akouō (κούω), to hear, and metréo (μετρέω), to measure. Neologism introduced in 2002 by Francesco Rampichini to indicate the "code of geometric proportions auditorily perceived in the acoustic representation of spatial perspective."
This code establishes a two-way link between graphic and acoustic sign, on the basis of synaesthetic perceptual nature phenomena, governed by the experience of visual perception in an audiographic representation of space.
As the geometry rise by the act of measuring the earth (gea) and is, in a wider sense, the science of proportions and measurement (lines, surfaces, solids), the A. studies the correlations between sound patterns and geometric shapes evoked to listening by analogy. This analogy is based on three main relationships between acoustic and geometric parameters: volume (dynamics) for the distance, pitch (frequency) for the vertical position, stereo (pan) for the horizontal position.

The acousmetric space
The A. arise from a gesture, as simple as the passage of a pencil on a sheet, translated into sound. The acousmetric representation and it’s syntactic organization allow to draw points, lines, polygons, surfaces and volumes in the abstraction of the " hearing paper".
Conceived by composer Francesco Rampichini and formalized in collaboration with the architect
Ettore Lariani and the physicist Marco Maiocchi to the Faculty of Design at the Politecnico di Milano, the A. has not be confused with the acousmatic. Even if the two disciplines have points of contact, they are totally different. The term acousmatic, dating back to the tradition of the Pythagorean school1, was proposed by Pierre Schaeffer, known as the father of the concrete music, to refer generically to any noise that is heard without seeing the causes from which it derives. “Acousmatic” were the lessons of Pythagoras, that his disciples heard without seeing him, hidden by a curtain, "returning to hearing the full responsibility of a perception that is supported normally by other sensitive witnesses," as Schaeffer wrote. The acousmatic short isolate sounds from the visual context, and proposes it as a phenomenon in itself.

The acousmetric perception
The A. has some relation to this principle, seeking to evoke the vision of geometric shapes in the absence of the visual stimulus, using a little known cross-ability, though frequently in action, of our perceptions, called synesthesia.


Essential history and theory outlines

«By the mid-80s," writes Francesco Rampichini Acusmetria in the Introduction to the book Acusmetria. Il suono visibile (Franco Angeli, 2004), "the physicist Monica Zamboni told me for the first time about those singular intermetallic alloys based on nickel-titanium (NiTi) called memory form materials, for the production of which we speak of an "education of materials" by means of a treatment that allows you to store the final form that will be taken. The simplest example is an active element in the shape of helical spring that is to close completely by healing. This ability to change its status by changes in temperature, used to perform particular functions (sensor/actuator), places them in the category of "smart materials”, with characteristics of superelasticity and high damping of vibrations. Some aspects of their property struck me immediately for the analogy with the problems I was trying to solve in the acoustic-musical field, pushing me to associate the idea of ​​sound objects that could evoke an identifiable shape. Then I began to consider the possibility of creating sound shapes that produced a short circuit of perception. Some years later I reach to formalize the intent to establish a relationship between sound and graphic signs (point, line, surface), initiating attempts to create sound materials that evoke geometric shapes of varying complexity, without even a glimpse of how I could use them. The advent of the computer era opened a gap in this endeavor. Thanks to the new MIDI sequencer I could start designing the materials of simpler concept: points, a segment of a straight line, some curved lines.
"The idea of ​​being able to reach the description of audiographic spaces activated a compositional process that exploited these first similarities to the plane geometry.
 Several years later, during the courses with colleagues Lariani and Maiocchi at the Polytechnic of Milan, I proposed to define Acusmetria the principle on which these processes are based, and Acousmetric Shapes the sound objects involved in it. Submitting them to the listening of uninformed subjects, we found that we can represent a triangle in an almost unmistakable way, especially in the point mode, as the lines, that is continuous sounds, posed greater problems of perception (distortions). Followed squares, diamonds, pentagons, hexagons, heptagons, octagons, ellipses.
"The first experiment of superposition of these materials actually involve a circle and a triangle.
 The psychoacoustic impact revealed that the feelings produced by listening were more complex than the optical experience: the phenomenon, in terms of auditory perception, was by no means new and induced a sense of spatial delocalization unknown to me, due, as I discovered later, to the operation of the mechanisms of memory retention of the reference auditory points».

Application Areas

From an application point of view, the Acousmetry can be divided in many areas:

- Architectural A., which provides for the possibility of designing buildings starting from acousmetric scores.
- Artistic A., which deals with bimodal (audio/video) composition, creation or translation of pictorial or sculptural works in their corresponding acousmetric images.

- Environmental A., which deals problems of environment tracking (indoor and outdoor).
- Exhibition A., which deals with the reproduction of
"notable profiles" of exhibits objects and their localized perceptions.
- Medical A., that deals with developing in therapeutic and diagnostic methods and tools based on it. One of the latest perspectives for application development is the
perceptual diagnostic via acousmetric sound objects
- Interdisciplinary teaching A., using acousmetry for the synergistic learning of geometry and music.

Perceptual aspects of A. are then subject to specific fields of study such as the Psychoacousmetry, that studies the psychology of perception of sound shapes in humans, and the evaluation of cognitive and recognition abilities.


1The followers of the Pythagorean school were divided into two categories: the acusmatics or listeners ("followers of the heard things") and mathematicians or scholars; the first were provided with an esoteric and shallow teaching, while the latter were started to the deep teaching.


Some projects

External links

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