Soundings science storyboard

Soundings	Science
The ear and hearing Our ears are remarkable and dynamic organs that enable us to hear both a pin drop and a thunderclap. They have three sections: the outer ear, the middle ear and the inner ear.
Sound waves in the air are collected outside the head by the fleshy part of the outer ear (A). They are funneled down the ear canal (B) to the ear drum (C). These sounds then cause the ear drum to vibrate. The vibrations pass along a chain of three tiny bones (D) within the air-filled middle ear to a membrane in the wall of the cochlea (E). The cochlea is the snail-shaped chamber of the inner ear. When the vibrations enter the fluid inside the cochlea they move ultra-sensitive hair cells that send electrical messages to the auditory, or hearing nerve (F). This nerve then carries the impulses up to the brain. It is only when the brain receives these signals that we actually hear the sound.	A=pinna B=ear canal C=ear drum D=ossicles E=cochlea F=auditory nerve
Each ear produces its own sounds The snail-shaped cochlea (E) has two types of hair cells. It is the inner ones that send the messages to the brain. The job of the outer ones is to improve the sensitivity of our hearing. As the outer hair cells do this important task they happen to produce sound waves that travel back out of the ear. This means that as we hear, tiny sound waves pass out of the cochlea (E), through the middle ear (D) and into the ear canal (B). Our ears therefore produce their own sounds!
These sounds are known as otoacoustic emissions or OAEs. OAEs are very faint sounds, which is why we are not usually aware of them. They are so quiet that if we want to study OAEs we must use highly specialized equipment.
Examining OAEs OAEs can be examined by playing a test sound into an ear and then recording the unique sound that the hair cells of the cochlea produce in return. The photo shows that this involves fitting a small ear-piece snugly into a volunteer’s ear canal. The ear-piece is connected to a computer. Clicking sounds are played through a miniature loudspeaker housed in the ear-piece. A very sensitive microphone, also in the ear-piece, then picks up any OAE produced by the cochlea. The photo shows that the computer then displays the OAE as a wavy line on the screen.
The wavy line that you see, shown more clearly below, is an image of the sound wave, or OAE, that the cochlea has produced in reply to the clicks that were played.
OAEs are individual to each person’s ear, rather like a fingerprint is to the hand. This means that if we play the same clicks into two ears, two different OAEs will emerge. The actual OAE that an ear produces depends very much on the sound going inwards. So, as we listen to different sounds such as speech and music, a variety of unique sounds should also escape from our ears.
Research and OAEs Medical research aims to discover how the body works so that we can detect, prevent and treat its problems. Recording OAEs under strict conditions allows the workings of the cochlea, middle ear and ear drum to be examined as a whole. This has clinical applications and at present OAEs form the basis of a screening test for newborn babies. At the Institute of Hearing Research in Southampton a new recording technique has been developed which is in the process of being researched. It is hoped the technique will improve existing OAE methods as well as open up a whole new area of research with its own potential applications. The Institute of Hearing Research, which is based at the Royal South Hants Hospital, is jointly funded by the Medical Research Council and the NHS Executive South East Region. Both ‘pure’ and ‘applied’ research are carried out. The pure research investigates what OAEs can tell us about the workings of the ear. Applied research, on the other hand, involves thoroughly checking the practical uses of OAEs in diagnosing hearing problems. Overall, the work of the Institute offers an example of the vital, yet behind-the-scenes, aspect of hospital life that is medical research.
The Live Event The Soundings live event has a double purpose: 1) a scientific demonstration of the how OAEs can be recorded, and . . . 2) an artistic interpretation of the sounds produced. To illustrate how each person’s OAEs are different, a scientist from the Institute of Hearing Research will test volunteers and project the results onto a large screen. These will then be traced by an artist so that the readings overlap. As the tracings build up, an interwoven pattern emerges. This suggests some of the hidden ways in which our senses respond to the world around us and to other people. The screen will then become part of the exhibition.