A certain use of piezo can be defined as stethoscopic when the movements performed with the contact microphone on the body of the instrument, recall the ones of the stethoscope on the human body. As a clear example, I can refer to my piece for piano and electronics PianoMusicBox_1. In this piece two piezos are used – one is given to the pianist for the production of sounds and one is fixed on the soundboard, providing information to the electronics. The piece starts with a few gestures, produced by exploring with the piezo the inner part of the instrument – the soundboard and the strings –, and it gradually moves toward the more familiar piano sound-world, when the pianist finally reaches the keyboard. The pianist's movements with the piezo inside the stringboard of the piano resemble the physician's auscultation with the stethoscope.
Sterne chooses an advertisement of Brandes of 1925 – in which the use of headphones is encouraged to improve the listening experience – as the endpoint of a series of transformations in practical orientations toward listening that began in the 1810s with the invention and adoption of the stethoscope in the medical diagnosis. Even the iconography of listening linked to early sound-reproduction technologies, especially concerning the use of headphones, points out a direct line of descent from the stethoscope, and the telegraph, to the telephone, phonograph, and radio.
The understanding of listening from a technical, scientific and rational perspective, started when listening entered as the practice for medical examinations of patients. Then, over the course of a century, this practical orientation moved from the specialized realm of medicine to the much larger context of listening to technologically reproduced sound. Sterne uses the word “technique” making clear the distinction from the term “technology” that could easily fade into the first one.
Technique connotes practice, virtuosity, and the possibility of failure and accident, as in a musician’s technique with a musical instrument. It is a learned skill, a set of repeatable activities within a limited number of framed contexts. Listening involves will, both conscious and unconscious—perhaps a better word than will would be disposition or even feel (Sterne, 2003, p.92).
So, techniques of listening come as a learned skill, necessarily resulting from an educational process, "whether institutionalized in professional training or simply accomplished through shared and repeated practice” (Sterne, 2003, p.92). Listening techniques emerged as a distinctively modern set of practical orientations toward sound and listening, and what Sterne presents is a set common to medicine, telegraphy, and sound-reproduction technologies.
First of all, in these contexts listening becomes a technical skill, used toward instrumental ends, which could be developed up to virtuosity. Moreover, listening has been constructed as a rational and discrete activity, ideally separated from other sensory activities. And, once reached the ability to separate hearing from the other senses, listening techniques helped to create a private acoustic space, that can be shaped and transformed. Finally, this private acoustic space comes with a specific content: it is inhabited by sounds that become signs, on the basis of their sonic features and their meanings. In fact, technical notions of listening depend also on the establishment of a code used to describe heard sounds, even if this code borrows its main terms from other sensory experiences, especially from the visual ones.
The emergence of a shared code, in addition to the development of listening techniques, provided prestige and professional ethos, especially in the specific fields of medicine and telegraphy, where the ability of representing listenings were part of professional expertises of both doctors and sound telegraphers. For both professions, an auditory technique is a premise for some form of physical distance and some mediating practice or technology. The faculty of isolating and intensifying hearing, promoted by mediating practices or technologies, was a component of rationalization of listening, which has been turned into a required skill. Medical listening, for example, provided new clear meanings to the interior motions of the human body, and hearing, in medicine, surpassed sight as a diagnostic tool through the use of the stethoscope for over a century.
The invention of the stethoscope is credited to René-Théophile-Hyacinthe Laennec. In 1819, he published the Treatise on the Diseases of the Chest and on Mediate Auscultation, in which he explained to physicians the reasons to prefer listening to patients’ bodies with the stethoscope, how to listen properly with it, and how to interpret the sounds thus heard. The first models of stethoscopes were monaural instruments. Their shape was cylindrical with an earpiece at one end and a hole at the other that would be placed on the patient’s body. These first models looked like an extension of the ear trumpet, which had been in use for centuries, with the main difference that doctors used them not as hearing aids but to augment their auditory abilities. Later, rubber tubing was used to make the middle of the instrument flexible, while around 1850 the binaural stethoscope appeared, designed by Arthur Leared. The binaural model quickly found favour because it provided sound to both ears, further helping physicians to isolate from other sounds and concentrate on sound in their specific auditory fields.
As one of the most enduring symbols of modern medicine, the stethoscope represents a key object in the development of a listening technology, connecting the faculty of hearing to that of reason. The practice of listening to the movements inside the body with the aid of an instrument has been defined mediate auscultation for the first time by the same inventor of the stethoscope Laennec. In his treatise, the term was used in opposition with the practice of immediate auscultation, i.e. the habit of listening to a patient's body with the naked ear, without any instrument to mediate in between. When promoting the use of the stethoscope Laennec insisted on its instrumental role, drawing a clear line between the use of the stethoscope and the one of listening directly to the human body (which is itself also actually conceived as an instrument for listening, as Sterne highlights). In the construction of modern medical knowledge mediate auscultation becomes central as a discrete, mediated, skilled, and technologized form of listening. Mediate auscultation has soon become a highly structured activity that requires deep knowledge and practice to perfect. Physicians need thorough ear-training and practices in order to turn instrumental listening into a point of access to medical knowledge. The stethoscope has been considered as a means to an end for the enhancement of medical perception. In this context, Sterne observes a rise of empiricism, towards a new emergent understanding of perception and its practice. Physicians have been asked to develop skills of concentration and abstracting in order to direct their attention only to specific sounds that had to be analysed. The stethoscope compensates for some of the insufficiencies of the human ear, but it also helps to isolate the faculty of hearing from the other senses, avoiding conduction of audible vibration by other parts of the body than the ear. Hearing is thus developed toward an ideal autonomous state, separated from the other senses, especially from touch and bone conduction. Hence, the stethoscope helps in creating a physical distance between the subject and the object of the listening experience. The stethoscope permits also to put a frame around some of the heard sounds, providing a clearer distinction between interior and exterior sounds. And this possibility of framing sounds facilitates their understanding, their analysis and diagnosis. Many aspects associated with listening, listening with technology, and the sounds heard via listening with technology, are enclosed in the practice of mediate auscultation. And, as Sterne points out, most of these aspects have been transposed in the music realm from the very first development of sound-reproduction technologies. For musicians, listening soon becomes a technical skill, used toward instrumental ends. A skill to be developed up to virtuosity. With the introduction of sound-reproduction technologies, listening is understood from a technical and rational perspective. In this context, the microphone can be compared to the stethoscope, considering both of them as an extension of the human ear, as technical objects that enhance the usual listening possibilities. The microphone becomes the instrument to turn listening into a mediated practice.
An explicit comparison between the use of the microphone and that of the stethoscope has been expressed by Stockhausen in Mikrophonie I. Here, a condenser microphone is used (rather than a contact microphone), but the German composer clearly explains his intention of using it to fulfil a listening function. Instead of considering the microphone as a rigid and passive recording device to reproduce sounds as faithfully as possible, Stockhausen prescribes to the microphonist actions to be done on the tam-tam, probing “the surface of the tam-tam with the microphone, as a doctor probes a body with a stethoscope”, as the composer writes in the preface of the score. The microphone gains a central role in the listening experience, up to the possibility to shape it. Through this very close listening, Stockhausen aims to bring to the front sounds of the tam-tam that otherwise would remain inaudible. Microphones co-operate in the definition and the perception of a peculiar auditory space inhabited by a previously hidden multitude of sounds. A listening experience mediated by such a use of microphones resembles the way doctors learn to restructure their own auditory space through the use of the stethoscope. In this sense, microphones share with stethoscopes the feature of a framing device. In medicine, mediate auscultation helps in distinguishing internal sounds that have a diagnostic meaning, from external ones, that have to be ignored. While in music, the opportunity to shape the auditory space allows for a better understanding of the musical material, and for a discrete and conscious form of listening. Intended as such, listening is oriented to the definition of a private acoustic space, in which each framed sound might assume a different meaning.
Experiences of mediated listening using contact microphones tend to highlight these aspects even more, producing a significant shift in the usual listening perception. When connecting a contact microphone to an object, the vibrations amplified are those of the specific point on the solid surface of the object where the microphone is placed. The contact microphone tends thus to resonate differently at different points of the material. Usually, the sound amplified through a contact microphone contains fewer frequencies and a stronger presence of pitched material, compared to the richer unamplified sound of the object. Moreover, a contact microphone usually has resonant peaks of its own, around certain frequencies. Thus, a process of filtering naturally happens when using a contact microphone. The sound heard will be then the sum of the "filtered" sound of the contact microphone and the unamplified sound of the object itself resonating through the air. This is the main reason why a consistent shift in the usual listening perception happens when using contact microphones. Sound is perceived as much larger and artificial, and the physical distance between the listener and the object of listening is perceptually reduced: sounds within the frame appear closer.
As already mentioned, Cage was among the first to explore sounds that are perceived differently through amplification with contact microphones, and to incorporate these sounds in his own sound material. The most relevant historical example in this sense is Cartridge Music. Here piezo-ceramic phono-cartridges from record players were turned into contact microphones and used to explore and manipulate different objects by actions such as scraping or plucking, etc. By performing with phono-cartridges, various sounds are elicited, uncovering different sound qualities of materials and revealing the unexpected richness of a whole set of amplified “microsounds”. This unusual proxemics of sound is rendered even more evident by a stethoscopic use of piezo, which activates spontaneously a very different way of listening. Amplification becomes clearly audible: due to its irregular frequency response curve, the piezo is devoid of features of sonic transparency. The piezo presents, in fact, very specific acoustic properties, such as the pronounced resonant frequency of its own, that confers it a peculiar colour. Thus, working with piezo means to mark even more the sonic presence of a technological tool between the acoustic sound of the resonant object and the human ear.
In most of my works, the musician is asked to perform a few actions with the piezo on the instrument, disclosing a different perception of the instrumental sound. Similarly to the stethoscope, the piezo has to be moved on the instrument's body, on its strings, or on its surface. In this way, the piezo captures the sound in a very close way while activating it, picking it up from different points of the vibrating surface. According to its resonant frequency and the inner resonances of the instrument, the piezo reacts differently at different spots of the instrument. Such stethoscopic use of piezo on the instruments tends to reveal to the human ear very intimate sounds, highlighting the sonic materiality of the instrumental sound, while calling into question the usual habits of the listening experience. Hearing is thus projected in a sort of hyperreality in which the instrumental sound matter is perceived as a fabric looked at through a microscope (listen to the audio example 2.1.1). The mediation of the piezo facilitates the building of a private auditory space, in which the actions of putting a frame around different sound objects and zooming in on the instrumental sound matter become more straightforward. Such renewed understanding of the sound material comes then to be a pivotal aspect within the compositional process, which can be itself understood as an advanced form of technical listening, as I will discuss more in detail later.
This comparison between the piezo microphone and the stethoscope opens up a few considerations on the listening experience. In his book The Audible Past, Jonathan Sterne dedicates two chapters to the genealogy of modern techniques of listening, and to the way their meanings changed in relation to three very different cultural contexts in Western Europe and the United States: modern medicine from the 1760s into the 1900s, sound telegraphy from the 1840s into the 1900s, and sound-reproduction technologies between 1876 and 1930. Early in the twentieth century, thanks to the diffusion of the telephone, the phonograph, and the radio, the appropriate techniques of listening became widely spread. And Sterne observes how their development was transposed and elaborated from techniques of listening already evolved during the nineteenth century in the very specific field of medicine.