The Soundscape: Our Sonic Environment And The Tuning Of The World (25 page)

Another type of aerial projection is the events map, which measures the distribution and recurrence of sounds. By means of events maps, comparisons can be made between two locations (say two blocks in different parts of a city) and the more persistent or characteristic sounds would be conspicuously revealed. Material for the events map would have to be limited to a specific period of time and would be gathered by walking over or around the selected location. (In the case of a city block this might be a single excursion around the block.)

Another example of aerial sonography, which brings value judgment into play, is that used by Michael Southworth in his article “The Sonic Environment of Cities.” Here, after walking about the given territory freely, numerous observers were asked to comment on the sounds they heard, and the results of their observations were gathered together for display. The resulting map for a section of the downtown area of Boston shows where the acoustic designer could profitably begin his work.

Such diagrams are hints only, but perhaps this is all one should expect of sound visualization—a few hints which the ear can then follow up in its own way. It is easier for the inexperienced to absorb the salient information from them than from other types of graphic presentation, and that is to their advantage. The temptation of bad habits is no doubt still implicit in them, and it is for this reason that I conclude this chapter with a warning that no silent projection of a soundscape can ever be adequate. The first rule must always be: if you can’t hear it, be suspicious.

NINE

Classification

Why classify? We classify information to discover similarities, contrasts and patterns. Like all techniques of analysis, this can only be justified if it leads to the improvement of perception, judgment and invention.

Consider the dictionary—words slashed from their contexts and arbitrarily arranged according to their attack sounds. Yet, when used properly, the dictionary can contribute to the improvement of the language and can even provide us with inchoate thoughts and aesthetic moments.

Any classification system or taxonomy is surrealistic; for surrealistic art also depends on bringing together incongruous or anachronistic facts, which nevertheless somehow snap together to illuminate new relationships. The first such artists were the encyclopedists, who brought together strange groups of animals, vegetables and ideas for surrealistic family portraits.

Sounds may be classified in several ways: according to their physical characteristics (acoustics) or the way in which they are perceived (psychoacoustics); according to their function and meaning (semiotics and semantics); or according to their emotional or affective qualities (aesthetics). While it has been customary to treat these classifications separately, there are obvious limitations to isolated studies. My colleague Barry Truax puts the problem this way:

Disintegrating a total sound impression into its component parameters appears to be a skill that must be learned; and while it is probably one that is necessary for acoustic design, a soundscape cannot be understood merely by a catalogue of such parameters, even if that were possible, but only through the representations formed mentally that function as a basis for memory, comparison, grouping, variation and intelligibility.

In this chapter I introduce some cataloguing systems for sounds—those systems which seem to be useful for dealing with various aspects of the soundscape—and the chapter will end with a discussion of the chief problems remaining to be solved. These have principally to do with the integration of classification systems. If soundscape study is to develop as an interdiscipline, it will have to discover the missing interfaces and unite hitherto isolated studies in a bold new synergy. This task will not be accomplished by any one individual or group. It will only be accomplished by a new generation of artist-scientists trained in acoustic ecology and acoustic design.

Classification According to Physical Characteristics
     

Let us consider first a physical classification for sound objects. Pierre Schaeffer has spent much effort in devising such a system. Schaeffer’s concern is not really with acoustics but rather with psychoacoustics. He has tried to work out a paradigm by which it would be possible to classify all musical sound objects for the purpose of helping students to perceive their significant features clearly. He calls this a “solfege des objets musi-caux.” In his book he presents the paradigm in a table covering four pages. There are nearly eighty blocks in the table and many are further subdivided in a dazzling performance of French complexity. It would be useless to reproduce this table without Schaeffer’s several-hundred-page explanation and rationale. The paradigm, it should be stressed, only deals with single musical sound objects. To cope with compound or more extended sound sequences, either the chart would have to be extended or the sounds would have to be broken up.

The system may be useful for the detailed analysis of isolated sound objects, but I would like to suggest a modification of it which might help to render it more immediately useful for soundscape field work. The idea would be to have a card on which the salient information of a sound heard could be quickly notated to be compared with other sounds. In line with our desire to comprehend sounds as events as well as objects (p. 131), it would be useful first to give some general information on setting: the distance of the sound from the observer, its strength, whether it rises clearly out of the ambiance or is barely perceptible, whether the sound under consideration is semantically isolable or is part of a larger context or message, whether the general texture of the ambiance is similar or dissimilar, and whether environmental conditions produce reverberation, echo or other effects such as drift or displacement.
^m

A chart could then be produced consisting of the answers to these questions plus a general physical description of the sound itself. For this purpose we might use a two-dimensional approach. On the horizontal plane we will preserve the three components of the sound object discussed in the last chapter:
attack, body
and
decay
. On the vertical plane we will determine the relative
duration, frequency
and
dynamics
of the sound, to which we will add observations on any momentary
internal fluctuations
(technically called transients) and two new features, derived from Pierre Schaeffer:
mass
and
grain
.

These last two need an explanation. Mass is related to frequency. While some sounds consist of clearly defined frequencies or pitches, others consist of inextricably entangled frequency clusters. Such may be the case with the broad-band noise of traffic, a flock of birds or the pounding of surf. Sometimes the sound will occupy a fairly narrow frequency band, sometimes it will be broad-band. The frequency spectrum of white noise will extend across the entire audio range (20 to 20,000 hertz), though it may also be filtered down to occupy a quite narrow range, at which point it may even appear “tuned,” so that it could almost be hummed or whistled. The mass of a sound is where its bulk seems to lie. It is regarded as the predominant bandwidth of the sound. Indeed both mass and frequency are often present in environmental sounds and they may sometimes occupy quite independent positions in the spectrum, as would be the case with a sound consisting of a low throb and a high warble. As mass is composed of frequency clusters it can be indicated in the frequency block on our chart by drawing in its approximate shape.

Similarly, grain is a special type of internal fluctuation, one with a regular modulatory effect. It is accordingly contrasted with transients, which are isolated or irregular fluctuations. Grain gives texture; it roughens up the surface of the sound and its effects consist of tremolo (amplitude modulation) or vibrato (frequency modulation). The tempo of these modulations may vary from slow pulsing effects to rapid warbles of 16 to 20 impulses per second, at which time their grainy effect will be lost. Thus in grain, a tactile word, we again meet the convergence of the senses of touch and audition as individual impulses pass from their flicker state to smooth contours of pitched sound.

I have devised my own signs to indicate these various effects, as shown on the following chart.

SETTING

1. Estimated distance from observer:__________meters.
   
2. Estimated intensity of original sound:__________.decibels.
   
3. Heard distinctly (  ), moderately distinctly (  ), or indistinctly (  ) over general ambiance.
   
4. Texture of ambiance: hi-fi (  ), lo-fi (  ), natural (  ), human (  ), technological (  ).
   
5. Isolated occurrence (  ), repeated (  ), or part of larger context or message (  ).
   
6. Environmental factors: no reverb. (  ), short reverb. (  ), long reverb. (  ), echo (  ), drift (  ), displacement (  ).
   

Description of a sound event
.

The symbols employed in the chart are not intended as exact graphic analogues, but rather as a handy index of devices for students to use in notating the significant physical features of sounds quickly during ear training exercises. Comparison of the chief characteristics of different sounds might also reveal useful distinctive features for the study of sound symbolism. The chart is, of course, useful only for isolated sound events, but despite its limitations it will serve to throw many of the most conspicuous features of isolated sounds into relief, as we can show in some simple classifications.

Classification According to Referential Aspects
     We have ext to consider a framework which will allow us to study the functions and meanings of sounds. Most sounds of the environment are produced by known objects and one of the most useful ways of cataloguing them is according to their referential aspects. But the system used to organize such a vast number of designations will be arbitrary, for no sound has objective meaning, and the observer will have specific cultural attitudes toward the subject. Even a library cataloguing system is stylized and reflects the interests and reading habits of librarians and library users. The only framework inclusive enough to embrace all man’s undertakings with equal objectivity is the garbage dump.

The framework I present here is that which we have been using for one of the sub-projects of the World Soundscape Project, an extended card catalogue of descriptions of sound from literary, anthropological and historical documents. The only way we have of gathering information about the soundscapes of the past is through earwitness accounts by those who were there. From the first part of the book, the reader will know that I derived a great deal of information from this catalogue, which now numbers several thousand cards. The catalogue headings are arbitrary and have been built up empirically, but they do at least accommodate all descriptions we have encountered to date.