Are our eyes window to hearing loss?

A man cleaning his ear with a cotton swabHearing loss is a problem that cuts across all age groups. However, many people make up for it by reading the lips and gestures of people interacting with them, reports Sade Oguntola.

MR. Tayo Olukunle, a banker, had just
returned from a visit to his friend. Apparently hungry and seeing the wife in the kitchen, he querried, ”Darling, what is for lunch?.” Thinking he was not getting response from the wife, he dropped his cap on the sofa and moved towards the door, repeating himself severally.

He was however surprised by the wife’s response that she had answer him each time he called that she was making Pounded yam and vegetable soup for lunch. It had been a case of Mr. Olukunle not hearing too well and thinking that the wife just decided to ignore his question on what was for lunch that Saturday afternoon. Many people with poor hearing senses make up for it by reading the lips and gestures of people relating with them.

This can easily be individual as a case of the eyes making up for deficiency in the other senses of the body. It equally points to the fact that the eyes may not just be a window to the soul, they may also provide a clue on the state of your other senses. A study has shown that the eyes can provide clues on how well a person can hear, especially in diagnosing hearing problems in babies, very young children and in people who cannot actively take a hearing test, such as those with a brain injury, say from a motor accident.

The study author, Avinash Bala and a research associate at the University of Oregon in Eugene, pointed out that “When most animals detect a change in their environment, their pupils dilate and the quieter the sound, the less the dilation. One of the things you can use this for is to see when a sound becomes detectable.” According to him, “Whenever there is a change in our environment, the natural reaction is to turn and look at it. At the same time, the heart rate slows, breathing slows, and the pupils dilate to allow the ability to assess the threat of the change.

If the sound is repeated numerous times, and there is no threat detected, animals and humans quickly learn to ignore such sounds. This is known as habituating. Millions of people worldwide have some degree of hearing loss and according to the National Institute on Deafness and Other Communication Disorders, approximately two to three out of every 1,000 children are born deaf or “hard-of-hearing”. Because hearing is so critical to speech and language development, experts believe that the sooner a hearing problem is diagnosed in babies and young children, the better.

However, detecting hearing problems in infants and young children can be difficult, because they cannot respond to normal hearing tests as older children and adults do. Before coming to the conclusion that eyes may serve as a means of detecting those with hearing problems, the researchers recruited 22 healthy volunteers and asked them to listen to a variety of noises. In this study, the subjects kept their heads still by placing their chin in a chin rest while they were listening to the sounds and a camera was tracking their eye movements.

In the study, presented at the Association for Research in Otolaryngology meeting in Phoenix, they found that when a novel sound was introduced, the pupils in human eyes dilated, and if the sound was repeated many times, the volunteers quickly became habituated to the sound. To counter this habituation, the researchers varied the sounds. For 11 of the study participants, the researchers also asked when they heard a certain noise and compared those results to those obtained by the pupil response, and found that the results were very similar, within three decibels.

Diane Sabo, Director of the Division of Sudiology and Communication Disorders at Children’s Hospital of Pittsburgh, said the findings were “intriguing” and that a three-decibel difference was very small. Meanwhile, Dr Olabisi, an Ear, Nose, Throat surgeon at the Highland Specialist Hospital, Ibadan, said the eyes could provide clues on how well a person hears because mere looking at the face of a person can tell us whether such an individual has hearing problems or not. “If you talk to an individual, his response can be in the form of nodding, smiling, showing annoyance and so on. For instance if you abuse or praise someone, his bitterness or pleasure will show on his face.

“If you are talking to someone and there is a blank expression, it may mean the person cannot hear and so you know the person is deaf. If however the person gives a nod answer to a question, you know the person did hear. So in a way, the eye is a gateway to hearing. Dr. Olabisi said this is really no direct link between eyes and hearing though facial expression can indicate whether a person can hear properly or not. He explained that in trying to detect hearing problems in children under five years, a distraction test is done.

This involves asking the mother to hold the baby and another person told to hold a toy behind her back and then make a noise with it to see if the baby will turn to find out where the noise is coming from. Of course, a child that can hear well will respond while that with hearing problems will not respond,” he declared. However, the expert said the eye, as an organ can be helpful in detecting other health problems like diabetes, hypertension and even HIV infection.

The interconnectivity of the senses of the body that make one to try to compensate for a deficiency in another, according to Dr. Gboyega Ajayi, an ophthalmologist at Ojulowo Eye Clinic, Mokola, Ibadan may help explain the connectivity between eyes and hearing in individuals. Finally, he said, when one sense has problems, another one will become better to compensate for the one with a deficiency and if you consider this, it may be possible to pick some information about hearing loss when one studies responses from the eyes of people.