Sonification in practice/el

Η ηχοποίηση στην πράξη, για εκπαιδευτικούς σκοπούς, αποτελεί μια διαδικασία διερεύνησης κάθε δυνατότητας η οποία απαντά ουσιαστικά στο ερώτημα: «Πώς μπορώ με ήχο να αναδείξω ή να καταδείξω, μια ή περισσότερες πληροφορίες ή συμπεράσματα τα οποία προκύπτουν από μια κίνηση, μέτρηση, ή φαινόμενο το οποίο είτε υπάρχει είτε εξελίχθηκε είτε εξελίσσεται μέσα στο χρόνο;». Τα υπάρχοντα δεδομένα που έχουμε στη διάθεσή μας, οι συνθήκες και οι τρόποι συλλογής τους αλλά και ο εκπαιδευτικός σκοπός για τον οποίο η ηχοποίηση προορίζεται, είναι οι καθοριστικοί παράγοντες για την αξιοποίηση μιας ηχοποίησης.

Οι ακόλουθοι παράγοντες διαμορφώνουν και την σχέση των εκπαιδευτικών αναγκών τόσο με την έννοια του ήχου όσο και της συγκροτημένης παράθεσής του μέσα στο χρόνο, δηλαδή την έννοια της μουσικής.

Πτυχές της διδασκαλίας με ηχοποίηση ως μουσική πρακτική

The indisputable connection between sound and numbers—specifically, the concept of breaking down sound into frequencies or harmonics—provides a sufficiently structured framework for interdisciplinary teaching using sound, within which all aspects of STEAM can be addressed. Since the concept of time defines the sound phenomenon, the representational act of a sound effect cannot but be at the center of any pedagogical approach. Consequently, the organized arrangement of sound elements in time in a harmonious manner—both in terms of rhythm, intensity, timbre, pitch, and their positional placement on the musical scale, whether diatonic or not—constitutes a musical result. This rational organization can serve as a field for experimentation in musical composition, while the parameterization of all the above concepts can enrich any educational objective that depends on the evolution of a phenomenon over time or the conversion of data into sound.

Thus, we can reasonably distinguish the concept of sonification for educational purposes into three basic approaches:

• The symbolic

• The mathematical

• The adaptive

Symbolic Sonification

The reproduction of sound characteristics, namely: pitch, intensity, timbre, repetition rate (if any), and duration—which are linked to scientific concepts, terms, and quantities without being logically mapped to a data-set (data-mapping)— constitutes the subject of symbolic sonification.

A simple example would be to “sound-paint” a gray cloud using low-frequency noise and a white cloud using high-frequency noise. Another example would be a class of students representing the sound of rain by randomly tapping their fingernails on their desks. Another example that relates composition with music representation is the leitmotif. A leitmotif is a short melodic theme consisting of a few specific notes which, as a unique motif (pattern), is associated with a character in an opera and played by the orchestra, particularly in Wagner’s operas. A character’s leitmotif brings the character to mind throughout the entire work, whether the character is on stage or not! Translating this to a data series, such a leitmotif could replace the expected sound of a prominent low or high value (or a specific value or even a range of values) without having any coherence or arising from the neighboring data.

Mathematical Sonification

When pitch, intensity, timbre, rhythm (if any), and duration as sound-characteristics, runs through a series of data-measurements connected to a physical term, or a scientific concept, they form a logical map of one or more parts of that series (direct data-mapping). The sounding result of this match is mathematical sonification.

An example that perfectly illustrates the above distinction, primarily by exploiting the characteristic of rhythm, is that of the mechanism for audibly indicating the distance between a car and the one next to it while parking, a feature found in many cars. The repetition frequency of this momentary acoustic signal forms a repeating pattern whose rhythm varies (slow-fast) depending on the proximity data to the obstacle, which is detected with high precision by a sensor.

To understand the difference between symbolic and mathematical representation, we can adapt the previous examples as “unplugged activities” in a classroom. Mathematical sonification in the cloud example would occur if we defined a color threshold for white or gray and represented the droplets that make up the clouds with millions of frequency particles of minimal duration (sound nebulae) the droplets of which clouds are composed. In the example of rain, we would have a mathematical sonification if students represented with absolute precision, one by one, every raindrop at a specific time and surface area. Finally, in the example of “parking,” we would have symbolic representation if the students’ eyes took on the role of the sensor, where data would be estimated visually without absolute mathematical measurement.

Adaptive Sonification

It is a sound design or musical composition (by expanding this notion), resulting from mathematical sonification in which, however, methods of aesthetic sound-rendering are creatively utilized to meet teaching objectives in describing learning concepts.

Furthermore, the analysis of data-mapping methods in conjunction with the diatonic scale opens up a fruitful field for exploring teaching tools that allow sound to be processed in terms of musical composition. The use of MIDI for sound processing or the highlighting of musical motifs—which can serve as a starting point for creating musical compositions—perfectly extends adaptive sonification. In fact, the graphical representation of data (graphical display) can be creatively transformed into sound by treating the display as a two-dimensional scheme, or even a photograph as a three-dimensional image. The result is referred to as “schematic sonification”.

This adaptable approach broadens access to the auditory outcome of data sonification across a wide range of age groups and grade levels, inviting educators from other disciplines—such as Art, Theater, and Music, to actively participate in interdisciplinary teaching. An example of this approach has been implemented in the “Sounds of the Stars” scenario.

THE MIDI protocol. Why is it useful for sonification in school?

MIDI Protocol stands for Musical Instrument Digital Interface and was introduced in early ’80s as machine language allowing analog and later digital instruments interconnection. This language interprets several aspects of music performance and notation in an electronic format.

MIDI enables the user to receive, transmit, store and edit electronically produced signals that correspond to several aspects of music. Main parameters of these aspects include note-on, note-off, velocity, timbre and pitch. All these parameters can be stored as code in timeline fashion within a MIDI file. A MIDI file resembles the “program” in the form of a revolving cylinder or perforated paper used in late 18th c. music boxes or early 20th c. “pianolas”, which are musical automata. It is this characteristic that can be proved enormously useful for educational purposes, as numerous midi applications, sensors and programs are widely spread throughout the internet. Within the present WIKI pages sensors using MIDI in particular, are widely displayed.

In the following pages, practical ways to handle data sets coming either from measurements or from sensors are described as: Unplugged activities, Real-time sonification and ''a posteriori'' sonification.

A sonification activity consistes in the design and buidling of a sonification system. A sonification system can be accomplished in many different ways but 3 components must always be considered: 1) INPUT DATA; 2) MAPPING PROTOCOL; 3) AUDIO OUTPUT;

Data Input

Mapping Protocol

Audio Output

Unplugged activities

Real-time sonification

''a posteriori'' sonification