3_PHD | melioli

GHOST SPACES

NOTES ON THE PHENOMENOLOGY OF THE ACOUSTIC SPACE

Melioli Matteo

CHAPTER 1.

INTRODUCTION

Any space can be perceived through sound –we can all sense spatial geometry, we can picture the depth and height of a space even with our eyes closed. The sound reflected off walls creates an aural stimulus through which we become aware of the surrounding space, its properties and its shape. Space thus becomes ‘audible’: it is expressed with an aural manifestation which parallels visual and tactile ones. Through the act of perceiving we grasp the unique structure of things, their unique way of being that speaks to all our senses simultaneously: the perception of an image is an experience that involves the observer completely, as an individual, and with all his senses. Space perception is, therefore, a process in which sight, hearing and touch converge to generate a unified, continuous and consistent image of the phenomenon experienced.

Common sense shows that humans can transform the acoustic attributes of objects and geometries into three-dimensional images. Our sensorial capacity to ‘understand’ a space through its sounds can be called ‘auditory spatial awareness’ and it involves not only acoustic elements but also the way in which we experience space through our emotions and behaviour. Although there is a vast body of theoretical work concerning both the physical acoustics of enclosed spaces and the decoding of acoustic parameters, very little has been written on how people experience aural space and how sound is transformed into three-dimensional images.

In order to understand auditory spatial awareness other elements need to be taken into consideration and addressed, such as the fundamental aspects connected to the act of listening: sound awareness and spatial acoustics. Compared to other cognitive processes, for example visual imagination, the complex way in which our mind interprets sounds has not yet been fully explored or understood, therefore I have begun my research with some simple, but functional, principles. The first basic principle is that there are various stages in the process of aural awareness: the transforming of physical sound waves into neural images, the detecting and deciphering of the sensations they produce, the perception of the sound sources and the particular acoustic environment and the influence of, and on, the listener’s emotions and moods. This process creates a ‘continuum’ between two spheres of reality: from that of the actual sound produced to that of its effect and relevance for the listener in historical, artistic and phenomenological terms.

I begin by studying the various stages of this process separately, however it must be emphasised that each stage is an integral part of the continuum. In Chapter 2,a functional model of an auditory experience is described. Sound, in its physical form, is a pressure wave which carries sonic events, along with the various elements of which the particular acoustic space is made up of, to the person listening, thus creating a connection between external reality and the listener’s inner world through his sense of hearing. The physics of sound is, however, an extremely complex field, and the process of transmission necessarily involves various other elements connected to the acoustic properties of a particular space such as reflection, absorption or dispersion. When the various sound waves reach the inner ear they are converted into neurological signals which are then processed by the human brain, thus creating a sensorial connection between the external world and our inner consciousness. If we consider the continuum as a linear process, at one end of the line we have raw sensation – this is the bare detection of an auditory stimulus, which has neither meaning or effect, and as we move along the line there is ‘perception’ – the cognitive process by which our brain transforms the raw sensation into some kind of meaning that is closely related to the acoustic and physical space surrounding the listener.

When studying the continuum from the physical reality ofa soundup to the personal experience and relevance of that reality, it is necessary to stop and consider for a moment how human culture, and western culture in particular, has been exposed to the acoustic phenomenon over the centuries, and how this has produced certain models which continue to influence the perception of sonorous space. In Chapter 3, l will describe how the concept of the spatiality of sound emerged during the flourishing of the Ancient Greek civilisation and how it evolved during the Renaissance. This model suggests an analogy between sound and space because both share the same universal principles of harmony. It is therefore not surprising to discover that the same geometric proportions were used both when deciding the specific dimensions in a physical space and when judging consonance or dissonance in sounds. I proceed in demonstrating how this fact is crucial because it establishes a direct connection between music and space, culminating in the XVIII century with the concept that internal to the acoustic phenomenon there is a spatiality directly connected to sound itself. Sonorous experience is a perceptive phenomenon, but the object of this perception – sound- has internal ‘structures’ which determine its own particular form. As I outline in Chapter 4,the question of acoustic space appears as a problem internal to sound itself, a problem deeply connected to the ‘raw matter’ of which music is composed. Taking in account the idea of ‘consonance’ and ‘dissonance’ popular during the XVIII century, I present the patterns that control both the acoustic phenomenon and its mechanisms of spatialisation.

It is evident that the notion of space taken into consideration in Chapters 2, 3and 4, have little to do with the concept of proven physical space, in which objects are collocated, and in which sound reverberates. My study continues with the focus moving onto acoustic space conceived as the space created by the interaction of the sound and the architecture in which it is contained. In Chapter 5, Ianalyse how architects, scientists and musicians have come to understand, appreciate and evaluate acoustic space. Whereas in thepreceding chapters Ianalyse sound and its innate spatiality, in this chapter I proceed to shed light on how sound uses architectural space as a medium to manifest itself.

By exploring the work of Wallace Sabine, Hector Berlioz and Richard Wagner our vision widens beyond the field of acoustics because the sonorous experience becomes part of the listener’s sensations in relation to the shape of the setting and theimportance of personal memory and cultural upbringing. I will show, however, that in Berlioz and Wagner we do not yet have an architectural use of the acoustic space because both consider concert halls as a ‘container’ for the performance of a musical piece.

Architects, on the other hand, have a very different concept of sonorous space. For them sound is at the centre of a complex system of relations between the built up space, the distribution of acoustic waves inside it, memory and musical culture. One of the main properties of a space is its size, however, unlike scientific instruments, human senses cannot measure physical parameters. Our eyes perceive the size of objects in terms of height, length and width, distance and dimension from their relation to one another and distance from the observer. In architectural acoustics, however, our sense of hearing perceives ‘size’ as the total metric volume because sound permeates space as a fluid, enveloping objects and entering every empty corner. Although we cannot see a volume we can hear it: we can sense if we are in a small or large space, by listening we become aware of the surrounding place, its geometry and its materiality.

In Chapter 6, I outline how architects in the last century started to design sound by manipulating the form and the geometry of a particular space. In this chapter I also study the conditions which are necessary for an architectural space to produce sounds pleasing to the ear. By studying acoustics an architect can understand how sound and space interact with each other and I show that, when designing a theatre, it is not only important to adhere to an abstract model of proportions or to achieve a generic idea of harmony, but it is also the result of a study of the acoustic architecture of the past. Gustave Lyon, for example, focused his attention on the Classic Greek theatre whereas LeCorbusier studied the large assembly spaces of ancient Rome.

What emerges in this chapter is that ‘sound’ in architecture is not a phenomenon that is relegated to scientific disciplines, but a field of knowledge, a cultural element linking it with the past. Following Le Corbusier and Lyon’s indications I demonstrate how the relationship between culture and aural architecture is preserved and handed down from generation to generation through buildings which survive over the centuries. In this way the aural architecture of a specific building or space defies time and new generations are able to re-invent or re-interpret these ‘inherited’ spaces creating new cognitive frameworks, which in turn are employed in the design of new buildings and spaces. Cognitive frameworks are part of our sensory inheritance, and understanding the aural architecture of our predecessors allows us to understand that of the present day and consequently all new projects of acoustic architecture are based on acquired knowledge.

This proves that even in the last century sound was regarded as more than just a simple oscillatory phenomenon. In Chapter 7 it is shown how architects and musicians unanimously agree in comparing sound to an acoustic body that can be built around a listener or distanced away from him; just like a tangible object it can be shifted from one place to another. Like a piece of architecture, the acoustic space is created by assemblage, combining and superimposing. Together with sound, the architectural and musical avant-garde movements also question the traditional concept of ‘listening’: this now requires spaces specifically designed around the music, not mere containers for the sounds. Thus inChapter7 I describe three acoustic projects; the Philips Pavilion by Le Corbusier, the Prometheus’ Ark by Renzo Piano and the Bach Pavilion by Zaha Hadid. With a twenty year interval between them, the three projects show how, over a century, architecture has adapted to a new idea of acoustic space. All three projects, in different ways, have the same principal aim: to teach us how to listen to the acoustic events that surround us and the world in general, and to re-evaluate the function of sound and listener in the process of space recognition.

In the first chapters I explored sound from various perspectives: historic, physical and architectural, however I did not study sound as a phenomenon in its own right that is as a phenomenon connected to our sense of perception and influenced by the listener’s senses and physicality. The projects of Piano, Le Corbusier and Hadid all have in common the fact that they put the listener at the centre of the scene, and around him the architecture is designed so that the sound can be perceived in all its nuances. In the spaces described the sound is like a bodily presence, inhabiting a space and moving inside it. The notion of interior space here refers to, and contains, both acoustic and semantic aspects, because on the one hand it allows the reflection of the sound, while on the other it represents its movement, rhythm and form. The space of the pavilions in fact recalls metaphorically a sonorous body, and the shape reminds us of the undulatory, rhythmic and harmonic structure of sound.

Following this line of thought, in the Chapter 8, I focus my attention on the ‘acoustic object’, considered as an acoustic body: if sound is a body it therefore has an extension, a volume and a form, but how can the form of sound be represented? Moreover we should ask ourselves why it is important to try to represent sound. Why should we discuss its form or movement when these are attributes of visible bodies? The answer perhaps lies in the fact that sound is both an acoustic and a visual image. Sounds, however, are incorporeal and therefore we cannot rely on the same faculties that are used to analyse the properties of physical objects, (sight, and touch). In this chapter I try to show how, even in the absence of corporeal elements, a spatial structure can still exist. The first thing which proves that music has its own space is the very act of listening: sound is a phenomenon which is perceived externally by our body and this fact gives rise to the notion – be it intuitively – of internal and external. Sound is not a simple projection into space, just as space is not a mere container for sound – sound can define space and create metaphorical barriers inside which sounds exist.

In Chapter8, I also discuss how space is perceived through our sense of sight and our sense of hearing. Although there is an unquestionable link between sight and hearing, it must also be remembered that they each have their own specific language. The same can be said of visual space and sonorous space; although they both share the same criteria of succession, symmetry and rhythm one cannot substitute the other. In this chapter I also refer to the work carried out by Robert Pasnau and Casey O’Callaghan who studied the relation between sound and images. They maintain that the sonorous and the visual fields are not separate entities but two different visions of the same space.

If this is true we have to ask ourselves if it is possible to see sound, and if, as Le Corbusier and Renzo Piano affirm, sound is a voluminous body, is it possible to represent its form? Therefore in this chapter I study ways in which the form of sound is perceived, taking into consideration fundamental concepts of acoustic geometry and the work carried out by various sound artists, and in particular Bernhard Leitner. When talking about acoustic geometry I show how the language of geometry enables us to approximate the behaviour of a sound phenomenon and it also allows us to create a link between acoustic and visual images. Although not limited to this, geometrical acoustics is a starting point which cannot be avoided, and I begin by describing the acoustic behaviour of geometrically simple spaces, like for example, a room similar to a cube. The method adopted has physical foundations and a long tradition which goes back to the XVI century and the first acoustic experiments carried out by Athanasius Kirker. In the appendix there are notes (Note 3 on Acoustic Geometries) on acoustic geometry in which the nature and the implications of the methods used are fully explained. In previous sections I describe how sight, hearing and touch converge to generate a unified, continuous and consistent image of the phenomenon we are experiencing and I study relatively simple spaces, like a room. I examine the space created by sound and how this interacts with the process of perception. Finally I show how it is possible to describe and represent the shape of the sound generated within such space. Each of these steps refers back to the act of listening to sound, the fact of being inside a certain space and hearing the sounds produced there. The space can be the room we are in, or they can be spaces which have particular acoustic properties, such as theatres, churches or galleries. We know, for example, that an architectural space can alter our perception of the size, mass and intensity of a sound. The sound is ‘magnified’ by the surrounding space, but in contrast to an optical magnification, this is a very subtle process as it is a product of the form and substance of the surfaces present in the space. As seen Chapter 2 and 8, when we have a sonic reflection which arrives immediately after the direct sound, the aural size and position of the sound source seem greater. Although the actual amount of sound energy remains the same, if there is a transfer of energy to early sonic reflections, we have the impression that the acoustic chamber is bigger, late sonic reflections, on the other hand, are perceived as mere echoes of reverberation impairing our powers of perception. Thus we can alter the perception of a sonic space by ‘concentrating’ or ‘spreading out’ the sound in time and space.

In the final part of my study (Chapters 9, 10) I concentrate on the acoustics of certain places like the basilica of San Marco and the church of San Giorgio in Venice and some industrial buildings located in the area behind the city. In these chapters I explore and describe the acoustics of these spaces, and in particular the effects of sonorous distortion which occur inside the structures, for example the presence of echoes and how the sound moves and changes around the listener. I believe that San Marco, San Giorgio and these industrial buildings are acoustic spaces ‘par excellence’: places where the sound moulds itself into the space, where various types of acoustic variations and aural distortions are displaced to and from the listener. We know that in a closed environment the perception of sound is distorted, because we hear sounds reflected off the walls of the acoustic chamber. In my opinion these phenomena have a particular relevance: they illustrate how the visual and acoustic experience of a building can be very different in relation to the singular geometry of the physical space. Although a particular geometrical form can give rise to an acoustic space and aural distances which are very different from their visual counterparts, the aural perception of distance between speaker and listener can vary greatly when the acoustic space changes – for example in an enclosed space, with the properties of a cube, compared to a larger or more open space.

In the last three Chapters I take a closer look at the phenomenon of the echo, in all its manifestations, and in particular the echo inside the basilica of San Marco and the church of San Giorgio. It is common knowledge that a window extends our vision and therefore our perception of visual space through a visual connection between observer and an extended visual space, a mirror has the same effect extending our perception of space through reflection and an echo creates the same effect in acoustics, here the illusion of an extended space is perceived aurally.

I am convinced that these ‘illusions’ are not merely accidental, and, in so far as they can be considered anomalies, they shed light on the mechanisms which govern human perception, allowing us to consider space in a new way. When sight and hearing differ greatly, the visual and sonic constrictions falter and a previously unexpressed imagery resurfaces. It is at this point that a whole world corresponds to the transience of a perceived space, one unveiled by the creative force of the invisible, by the power of absence and dream, where architectures, far removed from the time and space of our perception, reveal themselves to our senses due to the strength of unconscious ties. My drawings, therefore, are to be considered as playful interpretations of such ‘illusions’, and driven by acoustic properties and anomalies, I collect, overlap and combine different architectures from different historical periods and locations in the city of Venice. With this experiment it is as if I am extending their meaning, by overlapping their acoustic space different realities come into contact, revealing unexpected mutual analogies and connections. The nature of this research is therefore empirical: a number of different types of architectural structures are selected, they are brought into close contact with one another, overlapped, and allowed to ‘react’ acoustically. It is as if some sort of ‘chemical’ reaction is triggered between the different bodies, a reaction in which parts of one space acoustically combine with parts of the others, in which existing architectures, through a process of intersecting and combining, unveil the existence of new spaces.

GENERAL CONTENTS

CHAPTER 1. INTRODUCTION

1.1 Acknowledgements

1.2 Abstract

1.3 Illustrations

1.4 Illustration Sources

1.5 Introduction

1.6 General Contents

CHAPTER 2. THE PHYSICS OF SOUND

2.1 Sound

2.2 The Physiology of Perception and Acoustic Location

2.3 The Propagation of Sound

2.4 Sound as Spatial Phenomenon

CHAPTER 3. THE HISTORY OF SOUND SPACE

3.1 The Pythagorean Scale

3.2 The Monochord

3.3 Figurative Numbers and the Concept of Analogy

3.4 Harmonic Proportionateness in Leon Battista Alberti

3.5 The Evolution of the Concept of Musical Harmony

3.6 Toward Tonal Harmony

CHAPTER 4. ACOUSTIC PATTERNS

4.1Tonal Harmony

4.2Consonance and Dissonance

4.3Dynamic-Hierarchical Order

4.4Dynamic-Temporal Order

4.5Dynamic-Sequential Order

4.6 Sound and its Spatial Quality

CHAPTER 5. SPACES FOR SOUND

5.1 Creating Spaces for Sound

5.2 Sound Design: an Historical Overview

5.3. Hector Berlioz and the Acoustics in Les Invalides

5.4 Richard Wagner and Bayreuth: Making Music Visible

CHAPTER 6. ARCHITECTURAL ACOUSTICS

6.1 Gustave Lyon and the Greek Theatre

6.2 Sound and Architecture in Le Corbusier

6.3 Understanding the Behaviour of Sound

6.4 The Design of an Acoustic Hall: Le Corbusier and the UN Assembly Hall

CHAPTER 7. ACOUSTIC PAVILIONS

7.1 The Philips Pavilion

7.2 Luigi Nono and Renzo Piano: The Prometheus

7.3 Zaha Hadid’s Bach Pavilion

CHAPTER 8. THE VISUALISATION OF SOUND

8.1 The Relationship between Sight and Sound

8.2 Where is Sound?

8.3 Geometrical Acoustics

8.4 Representing Sound

CHAPTER 9. THE ARCHITECTURAL ACOUSTICS IN SAN MARCO

9.1 The Basilica and its Acoustics

9.2 Echoes

9.4 An Experiment with Sound: San Marco and the Chemical Tank CVM10

CHAPTER 10. THE ARCHITECTURAL ACOUSTICS OF SAN GIORGIO MAGGIORE

10.1 San Giorgio Maggiore and its Acoustics

10.2 Acoustic Collage

10.3 Acoustic Analogy

10.4 An Experiment with Acoustic Collage: Sansovino’s Library and the Rolling Mill

CHAPTER 12. CONCLUSION

APPENDICES

REFERENCES