The Movements of Air
Making Sound understandable to deaf persons
Excerpt from “How the Deaf and Dumb may be brought to understand, in some measure, what it is to hear, auribus audire”, by Charles-Michel de l’Épée (1784), published in English translation as an annex in John Pauncefort Arrowsmith’s The Art of Instructing the Infant Deaf and Dumb (1819).»
IN ATTEMPTING TO EXPLAIN THIS ARTICLE TO THE DEAF AND DUMB, I go to work as follows: I direct a large pan to be brought and order it to be filled with water. The water being perfectly settled, I take an ivory ball, or something similar, and drop it perpendicularly in. I make my pupil observe the undulation produced in the water, which would be much greater in a pond or river; but the deaf and dumb having seen this undulatory motion in both, call it to mind very easily. Then I write down as follows: — ‘I drop the ball into the water; the water being displaced, runs up and strikes the edge of the pan.’ Not a word of this is unintelligible to my pupils.
Next I take up a screen, or some thing similar, and flapping it in my hand, the curtains flutter and leaves of paper fly about. I blow upon the hands of one of my pupils with my mouth; and call all that air. Then I write down further: ‘the room is full of air, as the pan is full of water: I strike upon the table, the air is displaced and strikes against the walls of the room, in the same manner as the water is displaced and strikes against the edges of the pan.’ I now take out my alarum watch, and setting it properly, I make each of my pupils feel the little hammer which strikes against his finger with great rapidity.
I then tell him that we have all a little hammer in the ear; that the air being displaced in making its way towards the walls of the room, meets with our ear, which it enters, and causes the little hammer there to move in the same way that I make the corner of my handkerchief move with my breath. (This is the language I hold with them, and I think it right not to alter it here.)
After this I get a person who hears to stand with his face against the wall, and his back towards me, requesting him to turn round and come forward as soon as he hears me strike upon the table. I strike, and the rest is executed as agreed upon. I show that the air met with his ear, and having entered it, caused his little hammer to move, the sensation of which made him turn round and come forward.
I afterwards send the same person into another room: I strike and he comes back directly. I declare that the same operation has taken place in his ear, and served him for a signal to come back. It is thus we show that sound is propagated by means of undulating air. (We explain also why this propagation is slower than that of light.) As to what really takes place in the interior of the ear, anatomists will please recollect that we are addressing ourselves to persons who are deaf and dumb, consequently that physical exactness is out of the case.
The faculty of hearing, therefore, appears to them, an internal disposition of our ears, rendering us capable of sensations there, of which their own ears are incapable, because the door is shut so as to prevent the air from penetrating, or because they are without the little hammer to strike, or without the drum which it is to strike upon; and as they perceive that the stamping of the foot on the floor produces more or less motion at their feet, in proportion to the force of the stroke, so they conceive that the motion produced in our ears, is more or less felt in proportion to the degree of violence with which the air enters: they have nearly the same idea of it as of a wind blowing with more or less strength.
But as we can give no distinct idea of the difference of colours to a person born blind, neither can we give the deaf or dumb a distinct idea of the difference of sounds produced in our ears by the different articulation of letters.
- Charles-Michel de l'Épée
- Christine Sun Kim ,Speaker Drawing, 2012.
Excerpted from Charles Michel de l’Epée, “How the Deaf and Dumb may be brought to understand, in some measure, what it is to hear, auribus audire” (1784), in John Pauncefort Arrowsmith, The Art of Instructing the Infant Deaf and Dumb (1819). This text is part of Infinite Ear’s reading program, edited by Emma McCormick-Goodhart. Image: Christine Sun Kim, from the series Speaker Drawings, 2012, mixed media on 24 inch wood board.
is an artist whose work engages with the notion of the voice and its enunciation through radio broadcast, lecture-performance, and voiceover.