Sensuality and Proportion
A primer in sound for architects.

Acoustics - of hearing.

The word comes from an ancient Greek <akou-stikos>

To hear is to be sensitive to quivering, vibration, part of our understanding of space, which is a whole body experience involving not just the ear, and is synaesthetic: sight, sound, touch, smell and taste acting together.

1 Synaesthesia

A stone has audible, visible, tactile characteristics. It would be wise to duck, if the stone is coming in your direction. In the same way, when we are ambling through a city looking for entertainment, sounds of music, dance and singing are immediately attractive - evidence of conviviality and human company. Hearing is one aspect of a total understanding of an environment, inextricably linked to the other senses through the whole body.

To the right is a diagram exploring how the senses inter-relate.

Hearing operates over medium distances, whereas sight operates over vast distances.

Hearing is information of the air, like smell. It is ambient - giving a mood to the whole place - but alo pertinent: snookerball sized sounds operate in straight lines, heard with great directional precision like sight, but sound also is heard around corners through reflection and the resonation of the whole body of air. Listening is as much about understanding the landscape as hearing properly.

sight hearing smell touch taste
operates over vast distances


medium distances

city sized, room sized, and person sized

upper limits, reflection of sounds from the ionosphere

medium distances

up to a few miles

upper limits the smell of land from the sea

surface of body

near or touching



active:passive glows, beholds speaks, hears stinks, smells grasps, feels licks, tastes
visual form, shape, colour
rhythm, tone, timbre, balance, audible form
stinks, pheremones, toxins
heat, moisture, texture, tactile form, tremors, vibration flavour,
salt, sweet, bitter, sour
via electromagnetic vibration vibration of air, water, or other medium changes in concentration of volatile chemicals physical object food
in straight lines, frontwards, one dimensional in straight lines, and radially and by three dimensional reflection directional, radially and chaotically at body surface in mouth
using eyes/brain ears/brain bone, soles of feet, diaphragm nose/brain, nasal cavities skin, especially hands, feet tongue and mouth
The air is generally invisible audible - carrier of sound through quivering smellable, the carrier of smell through movement and chemical activity felt generally tasteless
wavelength size between 400 and 700 nanometers (10-9 m) 1.7 cm - 17 m and beyond
frequency 4 - 7.5 x 1014 Hz
1 octave
< 20 - 20,000 Hz
10 octaves

Hearing is:
- spatial
Not only does the ear gives us our sense of height, width, and depth - whose three dimensions are embedded in its anatomy [2]. We hear round corners, through open windows and doors, by inverse of distance, ambience - a radial, indirect model of space which demands our understanding only when it becomes important. Further the sounds we hear are gesture sized, body sized, room sized, from. The average size of sounds we can hear is about the distance from mouth to belly.
- sensitive
to pressure fluctuations, and spatially accurate at appropriate sizes [3] - gesture-sized sounds and sibilants [4], so sensitive that there is no such thing as silence
- temporal
It tells a story which unfolds in time [5] - we experience tiny variations in time [20-20,000 vibrations per second] compare sounds, remember the space we have come from and anticipate the glimpsed spaces to come. Hearing is a personal story and soundtrack which begins before birth and ends after death.

Whilst each individual's acoustic experience is unique - we are all at different ages of growth and our pinna (outer ear) is all complicated and difficult shapes, each side different, and our way of experiencing sound is characterised by our culture, physiognomy and experience - acoustics draws out of the personal experience what is common, essential, teachable. We search for the objective communal experience, spurred on by the subjective experience of ecstasy. Valuable sound is a vehicle for communal history, song, dance and religious contemplation, healing and balance.

2 Branches of acoustics: Acoustics impinges on architecture in these areas
performance of speech and music music
noise control and high fidelity acoustics
- speculative acoustics - listening as a means of understanding whose grandfather is Pythagoras
- actual expert experience, universal

'...the eye is never satisfied with seeing, nor the ear with hearing...' [Bacon]

As a discipline or a mode of enquiry, listening is ancient. The healing/sacred qualities of tone and dance rhythm, and music evidenced by the surviving artefacts of the earliest communities. Attributed to Pythagorean of Samos c580 BCE, is the comparison and measurement of the length of pipes and strings, the beginnings of a quantifiable mathematical ratio of sound, and its application as a philosophy for explaining the world, although an earlier Babylonian text describes the tuning of a lyre, and the mathematical principles of are built into the manufacture of pipes and lyres themselves.

The study of musical harmony was one vehicle by which man drew together the vast complex of information into an orderly precision. It enabled things of different size to be conceptualized in relation to each other, into a vast ladder of correspondences from the greatest to the smallest. At once speculative and practical. We hear by comparison: of time, of size.

The measurement of strings and pipes was studied in ancient times, but mathematised in the C18 in France with a great renewal of interest in Pythagoras where the vibrations of a stretched string where mathematically understood. Modern Acoustics evolved in the late C19 with a desire to quantify the amount of energy expended. Milestones were the publication of Helmholtz's 'On the Sensations of Tone' in 1877, and Rayleigh's 'Theory of Sound' in 1878. Architectural acoustics began with Sabine's work on reverberation, begun 1895 and published in 1900. Sabine's breakthrough - to put aside all thought of harmonic proportion and view sound as energy.

Contemporaneously, sound began to be measurable, recordable, visible, through mechanical instruments of the air, for example gas manometers, and then electric instruments: the microphone and the cathode ray tube in the C20. By the late C20 recording measuring, displaying sound visually, amplifying it, reproducing it, has become incomparably easy and approximate, with this has occurred a paradigm shift in our sound use in everyday life. We carry not only the earphones but he concert hall as we travel by tube.

The task of acoustics, for the architect, is one of exploring and understanding living space - exploring the sound of a city and the human place within it. This involves a very detailed study of water, of relative silence, and our commitment as a community to listening.

In music, acoustics studies how sound is produced and dispersed - sounding bodies and disposition of sonic forces
In architecture, acoustics studies the sonic properties of partially enclosed spaces, how spaces shape and modify sound.
In physics acoustics is concerned with the propagation of vibrations in a fluid medium
In metaphysics acoustics is concerned with 'the edge of reason' - harmonic and chaotic relationships and correspondences between things large and small - the issue of scale and comparisons.
In our actual life ,we are already expert, and can benefit from a framework on which to hang our expertise.
index | hearing |
[1] For further notes on the word and its etymology/use
[2] see ear
[3] Through other organs than the ear we hear below these frequencies
[3] Traditional fairground trick - a bell and a thrown knife
[4] sibilants= the whispering sounds.
[5] Feedback loops.
[6] Give the senses of the air their proper weight in the total picture. In the present time there is a tendency to underestimate them because the air is generally invisible. But if we examine for example who people choose as their friends or their mates, smell has a great deal to deal with it.

[7] Hearing colours

© Marcus Beale 1999-2006