The following note was prepared by the teacher of the deaf of a girl whose parents were seeking NHS funding for a bilateral CI. It gives a good practical insight into the limitations of monaural hearing and the importance of binaural hearing:

S is a very good listener, having had her cochlear implant for nearly 4 years. She is able to access the curriculum by listening and learning through spoken language. She has developed very good spoken language herself. In the school environment S is helped to attend to the classroom teacher’s voice with the aid of a radio-aid which overcomes some of the problems of distance and noise. The class teacher also uses a soundfield system to enable her voice to be heard at the same volume throughout the classroom.

At present S is unable to localize sound as she only has hearing facilitated in her left cochlear with the cochlear implant. With her implant she hears on one side at a level of a mild hearing loss, but only across the speech spectrum.

There will be times when S is disadvantaged by having unilateral hearing (one-sided hearing because of only having one cochlear implant). Being able to participate fully in group conversations is increasingly important in education today.

• Class circle time. The children are answering questions or giving their opinions from around the circle on the carpet. S is unable to locate the speaker except by using clues from the rest of the class which entails a time delay, and she is less likely to understand the comment that she hears because it is not related to a person. Often the comment is accompanied by a visual response which might be holding up something or pointing to something. S is likely to miss this too. The speed of the lesson is often such that there will be many such comments, a proportion of which S will miss because she is unable to locate the speaker except with some visual support from the class teacher which will involve a time lag.
• Group work. Much of a child’s learning takes place in small groups in primary school. This includes formal discussion of a topic as well as informal conversation between children. S is unable to locate the speaker and is therefore having difficulty participating fully. Her understanding will be hampered by being unable to focus in on the speaker so that she can use the facial and body cues in everyday speech and the visual cues often used in school to aid learning.
• Active lessons like PE and drama. Being aware of one’s space in an activity is aided by bilateral hearing. This is a time when there is more active learning if all the sounds and voices can be interpreted sequentially and spatially.

• Participating in social activities in any size of group above two people is difficult with one-sided hearing. Conversation moves rapidly between speakers and it will be difficult for S to keep up with who is speaking.
• There is more security in being able to tell where people and other noises are around you, giving confidence in a group situation.

• As S grows up she will be expected to take more responsibility for her own safety. The ability to locate sound will be very important for being able to cross roads and ride a bike safely. It may be important in knowing the direction a warning voice or the sound of a car comes from.

• There is a considerable strain imposed upon S trying to follow conversations. There is a danger that a child with unilateral hearing will ‘opt out’ of these difficult situations and not take part.
• There will be a feeling of insecurity in not being able to predict where someone is coming from or what a noise might mean depending on where it comes from. Although S is very good at listening, her inability to localize means she cannot always interpret the sounds she hears with accuracy.

Within the UK the policy is to aid Deaf children bilaterally whenever possible. Unless there are practical reasons against it, all children are encouraged to use two hearing aids. Nowadays children with a cochlear implant are encouraged to use a hearing aid as well when they can make use of it. This has not been possible in S’s case because she is so profoundly Deaf. The result is that a bilateral cochlear implant is the only possible way of enabling S to gain bilateral audition which is the norm for many other Deaf children.

S had her implant before the age of two. This is becoming more common and early implantation means that children like S are developing age appropriate language enabling them to take part in mainstream schooling with minimal support. However, for the reasons outlined in detail above, there are significant limitations to the potential for good educational outcomes that arise from only having unilateral hearing in such an environment. These difficulties intensify as children move through the school curriculum and on to secondary school.

The above note was written at a time when S had a unilateral CI. She has since received a bilateral CI (see case study) after her parents self-paid for the operation having been refused NHS funding.