2020 June

Otorhinolaryngology, National Rehabilitation Center for Persons with Disabilities
Kotaro Ishikawa

Introduction

Last year, the Parliamentary Association for the Promotion of Policy Concerning Hearing Loss was established by Diet members. Japan Hearing Vision is a proposal put forward by the association. In addition, more attention is being paid to hearing loss, with the Ministry of Health, Labour and Welfare and the Ministry of Education, Culture, Sports, Science and Technology reporting on a joint project spanning health care, medical care, welfare, and education aimed at early-stage support for children with hearing loss. Against this backdrop, this article will cover everything from diagnosis to rehabilitation for children with hearing impairments.

Method for Diagnosing Hearing Loss

The widespread use of newborn hearing screening has enabled early detection of hearing loss. In newborn hearing screening, automated auditory brainstem response testing (AABR) or otoacoustic emissions testing (OAE) can be used to determine whether the infant’s response is normal or requires further examination. In cases that require further examination, the child is referred to a specialist hearing test center with an otolaryngologist to determine the hearing level using tests such as infant hearing tests, auditory brainstem response (ABR) tests, and auditory steady-state response (ASSR) tests. Identifying a need for further examination during newborn hearing screenings does not necessarily indicate true hearing loss, so caution is required when explaining.

Tests performed to find the cause after a diagnosis of hearing loss include genetic testing to find the gene that causes hearing loss, viral testing to diagnose congenital cytomegalovirus infection, and imaging tests using X-ray CT and MRI to diagnose abnormalities. This is based in data that indicated that about 60% of congenital deafness is related to the deafness gene, 10 to 20% is related to congenital cytomegalovirus infection and the rest are congenital abnormalities and other causes. Determining the cause can be helpful in choosing a rehabilitation strategy as described later. For example, if a mutation in the GJB2 gene, which is a common cause of hearing loss, is identified, it has been reported that cochlear implants are effective for severe hearing loss.

Because hearing loss often develops in early childhood, even when the child had a "normal response" during their newborn hearing screening, it is important to monitor the child's response to sound at all times and consult a specialist if in doubt.

Hearing Aids used for Children with Hearing Loss

Various types of hearing aids are used for children with hearing loss. The most commonly used hearing aids are air-conduction hearing aids, which are generally placed over the ear. If an air-conduction hearing aid cannot be used, such as in cases of congenital atresia of the external auditory canal, a bone-conduction hearing aid may be used. Recently, the use of cartilage-conduction hearing aids has also been recognized in some cases. If hearing loss is severe, cochlear implant surgery is performed. Cochlear implants are being chosen in an increasing number of cases of severe hearing loss, where hearing aids are ineffective. In addition, early-stage surgery and having implants in both ears simultaneously is being chosen in a growing number of cases. In addition, bone-anchored hearing aids or middle ear implant are sometimes used for cases such as congenital atresia of the external auditory canal. Adaptive FM and digital wireless technology are often used in schools to assist with the hearing of implements such as hearing aids and cochlear implants.

General Overview of Rehabilitation

It is known that the condition and prognosis of hearing loss in children depend on the type and cause of hearing loss, the time of onset, the degree of hearing loss and type of hearing, and the presence or absence of other disorders. There are also a wide range of training and instruction methods, including the auditory-oral method, the auditory-verbal method, total communication, sign language, cued speech, and combinations of these methods. As previously mentioned, there are various types of hearing aids used. Furthermore, in addition to guidance institutions and the hospitals and rehabilitation centers where I work, there are facilities for preschool children with hearing loss, special schools and classes for children with hearing impairments, local rehabilitation facilities, and private guidance institutions. The methods, principles, and forms of guidance differ in each facility. For this reason, while it should be important to select guidance institutions and methods upon consideration of the child's condition, ability and parents' views, but depending on the hospital or training facility visited, there is a risk that information may be biased. Under these circumstances, in order to support the diverse continuum of children with hearing impairments, it has become necessary for welfare and education departments to strengthen cooperation, improve the core functions of support for children with hearing impairments, and provide appropriate information and support to children with hearing impairments and their parents. To this end, from this fiscal year, prefectures and designated cities are planning to implement a model project for the core functions of support for children with hearing impairments is scheduled to be conducted at about 14 locations nationwide, with support from the national government. The project includes the establishment of a council, cooperation with related organizations, support for families, and rotating support for each facility. This makes it possible to provide appropriate information to all children with hearing impairments and their families, and it is considered to help link them to their preferred rehabilitation.

Basic Approach and Procedure of Rehabilitation

The purpose of rehabilitation for children with hearing loss is to help them achieve holistic development as an individual. In order to make this possible, it is necessary to adjust the content of classwork and support as they grow. It is important to provide guidance from a developmental perspective, to evaluate children's communication and language abilities and design individual programs, to take an approach based on communication that is carried out in situations that are meaningful to children, and ultimately to guide children toward autonomous learning.

As children age, they grow from infancy to early childhood, and to elementary school age. Rehabilitation programs are planned in accordance with this timeline, but from the viewpoint of language development, it would be possible to carry out rehabilitation with more detailed consideration if issues are considered separately for the pre-language stage, early language acquisition stage, language structure formation stage, and language maturation stage. When designing rehabilitation programs, the following points should be taken into consideration: (1) overall development of movement, cognition, emotion, and interest; (2) communication attitudes, methods, and interrelationships; (3) language acquisition and processing abilities; (4) degree of auditory use and use of other sensory modalities; (5) understanding and support of parents; (6) environmental adjustment of family, community, and education; and (7) selection support for the first language and communication mode. With this in mind, a cycle is established in which the child in question is evaluated, a rehabilitation program is created based on the results of the evaluation, training and guidance are conducted, and then reevaluation is conducted to adjust the training as necessary.

Key Points in Rehabilitation

Rehabilitation is a collaborative task undertaken by patients themselves, their parents, and the rehabilitation staff. In addition, various people in the patient’s life (family members, friends, school personnel, etc.) are involved in many aspects. When we talk about rehabilitation for people with hearing impairments, we tend to focus on enabling the patient to speak a language. However, as I mentioned earlier, various efforts need to be made to enable the patient to achieve holistic development as an individual. It is important to understand that rehabilitation guidance concerns not only language acquisition, but also a wide range of aspects. In language acquisition for children with hearing loss, it is necessary to pay more attention to the input aspect and information processing process of “listening and understanding” rather than to speech itself. When perceptual processing of spoken language is being formed, it is necessary to promote the use of hearing and reading. Additionally, in communication situations, information is conveyed more easily and accurately by also using expressions and gestures. Linguistic and non-linguistic understanding is important for communication. In order to develop communication skills, it is necessary to learn to communicate about communication itself (metacommunication). In addition, to aid with the contextual understanding of environmental sounds, it is important to build upon a foundation of meaningful auditory experiences in daily life from infancy. Guidance by parents is also important, and therapists must present appropriate models so that life experiences and communication can be made concrete according to the child. On the other hand, it is necessary to pay consideration to the psychological state of parents, avoid excessive demands, and show a willingness to work together. Guidance toward self-advocacy (explaining and helping others understand the support you need) is also important for older children with hearing impairments.

Conclusion

This article has covered diagnosis, hearing aids, and rehabilitation for children with hearing impairments. Space limitations prevented a more detailed exploration of the topic, so interested parties should refer to literature for more information. I hope that many people will deepen their understanding of children with hearing impairments and that an environment is created where these children can receive appropriate rehabilitation and play an active role in society.

Notes

GJB2 Gene

Coding gap junction protein, one of the tissues that connect cells, this gene mutation disrupts the flow of potassium ions in the inner ear, causing hearing loss.