The science of sound


SYOS process is based on the combination of two different disciplines: musical acoustics and psychoacoustics. SYOS mouthpieces were developed after 5 five of research in these two domains. Today, SYOS offers an infinity of new geometries to the musicians, which allows to shape the sound aesthetics regardless of the material used to make the mouthpiece.



Musical Acoustics







Psychoacoustics, what's that ?

Psychoacoustics is the study of sound perception. This research domain merges physics and psychology, in order to understand how sound waves are perceived by our ear and how our brain interpret the resulting signal. Why some sounds are perceived louder than others? What defines the pitch of a sound? How are we able to distinguish an instrument from the others? The psychoacoustician brings answers to these questions in an experimental way, by performing listening tests on humans and by studying the way they describe what they perceive.

Through our history, we developed a quite accurate and consensual language to describe what we see (shapes, colors, textures...). However, describing sound sensations with words is still difficult. The German physician Hermann von Helmholtz was the first to establish the link between instrumental timbre and physical quantities. Since his work, several researchers focused on auditory perception, and the study of the timbre perception is still a wide research field today.

In order to establish relationships between what perceives a listener, what he describes and the sound signal properties, the psychoacoustician uses methodologies derived from experimental psychology, combined to statistical analysis. A typical psychoacoustical process is presented on the scheme on the right: in this example, the goal is to explore similarity and dissemblance relationships between several sound signals (A, B, C, and D) that are presented to several listeners. The dissemblance is modeled by statitical methods, which directly link what is perceived by listeners and the physical properties of the signals.




How does it relates to musical instruments ?

The previous methodology, in addition to other kind of similar analysis, can be used to assess how the musicians perceived the musical timbre. A famous example in the academic world is the timbre space of Stephen McAdams, which is represented in the figure on the right. By conducting the above process on sound signals corresponding to the same note played by different musical instruments, McAdams determined the similarity relationships established by our brain between the timbre of these instruments. No less than 88 musicians participated to the study! The experiment was a pairwise comparison of 18 sounds, the task given to each listener was to indicate on a scale a rating of dissemblance between each pair of sounds among the 18. An average perceptual space was constructed by statistical analysis of the listeners' answers.

The results of McAdams underlined three major criteria that we judge when we try to identify and discriminate the musical sounds: the attack (which correspond to how fast the sound begins), the spectral centroid also known as "brightness", and the spectral flux, which correspond to the "richness" of the timbre.

Is this study applicable to saxophone ?

McAdams study was focused on the timbre of musical instruments in a generic way: saxophone sounds were not used in this study. Indeed, the number of sounds in such experiments is limited in order to keep the listeners involved and in good listening conditions. Imagine you spend several hours in an isolated cabin with headphones on your heads, while listening to more than 200 hundred pairs of sounds! Therefore the experimenter has to make decisions on which sound to use. Few scientific studies focused on saxophone sounds. Some researchers such as Jean-François Petiot in 2013 or Arne Nykänen in 2015 performed psychoacoustic experiments to explore the relationships between the saxophone timbre and the reeds or the body of the instrument.

Maxime is the psychoacoustician of SYOS. He's in charge of conducting perceptual experiments with musicians (professionals as well as amateurs) in order to establish the link between the different sound aesthetics and the new mouthpiece geometries designed by Pauline.


You live near Paris and you want to participate to a study ? Give us your contact information and we will schedule an appointement.

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How different the sound aesthetics can be?


Each saxophonist has his own way to play and his own criteria in terms of sound aesthetics. Listen to the three musical excerpts on the opposite: they correspond to three different tenor saxophonists. The first one, Stan Getz, has a really soft, dark and velvety sound. Getz skills in the mastering of this sound aesthetics have earned him the nickname "The Sound". The second excerpt is John Coltrane's Tenor sound, still soft but with more brightness, which gives him an edgy and nasal aspect. Finally, the last excerpt is Michael Brecker. The powerful, hard and very bright sound he obtains influenced a whole generation of saxophonists.