Hearing loss occurs in all age groups and significantly affects all aspects of our daily life. In children it causes a significant delay in speech development, and serious disturbances in the processes of learning.
The otolaryngologist is solely responsible for the detection and diagnosis of hearing loss and often the first, if not the only, source of information parents have about the various educational options and forms of communication that are available for families of children with hearing loss.
A highly consultative approach of the family requires a well-organized multidisciplinary team with professionals of various disciplines. The consulting of the hearing impaired and of parents of young children with hearing loss is a huge and important matter, starting from the time of announcement of the diagnostic audiology tests’ results.
Childhood hearing loss, that is, hearing loss that is present at birth or appears during the first years of someone’s life, is particularly important in comparison with a hearing loss acquired during adulthood. As mentioned above, it has important effects on the speech development of the individual and their learning process. Indicatively, children with moderate hearing loss will articulate their first word averagely at the age of 21 months and will acquire more vocabulary at the age of 36 months, while children with normal hearing start to speak at the age of 10 months and enrich their vocabulary at the age of 18 months. Unilateral or bilateral hearing loss results in children having problems in locating sounds, in speech understanding, especially in a noisy environment, while articulation is less than of children with normal hearing.
In the sensitive area of child hearing loss, immediately after the primary role of early diagnosis, should be careful selection and appropriate application of the right hearing aid. At the same time there must be the appropriate information and education for parents, who play an important role in the treatment of childhood hearing loss, which requires the assistance and cooperation of specialists in this field. In children’s cases of hearing loss, hearing aids are applied in both ears to achieve a better acoustic amplification, better localization of the direction of sound and additional improvement up to 20% in distinguishing speech, contributing to further development of speech.
The hearing aids selected and applied to children must have unique technical and operational characteristics. These are the specific internal settings, the large range of frequencies, the minute in size, anatomical, easy in external settings and to have audio input for connection to education (FM) and other audiovisual equipment (CD player). There are basically two kinds of audio settings: external, made by the user for proper operation and performance of the aid, and internal made from special applications (hearing aid applier) to better reproduce the sounds and especially the voice, free from noise and interference. These settings define the operating range of the aid, which is very close to the range of each audiogram, from the threshold of hearing to the threshold of discomfort, but gradually increasing (within 5 to 6 weeks) to adjust the brain to stronger stimuli.
The cornerstone in a possible successful treatment of hearing loss in order to prevent the serious consequences in the development of speech is prevention and early detection. Particularly on the prevention of hereditary hearing loss the latest developments in molecular biology with the analysis of genetic code allows us to more fully inform the relatives of the hearing impaired and the general population about the possibility of outbreaks of hereditary hearing loss. Specifically, the gene conexin 26 is responsible for 30% of sporadic individual cases of hereditary prelingual hearing loss in the recessive physical trait of moderate or large degree. There is also an increased frequency of finding the gene conexin 26 in Greeks (3.5% of the general population are carriers of the gene).
Early diagnosis of childhood hearing loss involves the hearing screening of newborns in maternity wards during the first days after birth. Such control has proven to be more effective and less costly than the screening hearing that was traditionally conducted with behavior testing at age 7-9 months. In addition to our arsenal of standard testing methods (causing reflex reactions after administration of acoustic stimuli, tympanometria, determination of reflex of the stirrup muscle, free field audiometry, tests with pictures, tests with games) there are two specific methods that do not require cooperation of the patient. These are otoacoustic emissions and evoked auditory of the brainstem. Because the hearing screening of newborns cannot detect acquired or progressive hearing loss that are developed later on, retesting of hearing is required to detect these occurrences that represent 10-20% of all permanent hearing loss in childhood.
The treatment of childhood hearing loss is surgical and conservative, depending on the type, form and degree of hearing loss and general psychomotor development of the child. Cases treated with surgery are those of chronic otitis, of secretory otitis (fluid collection in the middle ear), and varying degrees of malformations of the outer and middle ear. A surgical method is considered the placement of a cochlear implant in cases of bilateral deafness, which does not improve even with the most powerful hearing aids. The cochlear implant, one of the greatest achievements of 20th century technology is an electronic device that bypasses the sound treatment system and the cochlea and directly stimulates the ganglion cells of the auditory nerve. Implantation is followed by a long rehabilitation program (18-24 months and in some cases up to 4 years), involving otolaryngologists, audiologists, technicians, therapists and teachers of the deaf. The ultimate goal is for children, five years after implantation, to be able to use spoken language as their primary means of communication and their speech to be understood by an average participant.
The majority of small and large extent hearing loss is treated conservatively with the application of hearing aids. The aid should be applied in every case of unilateral or bilateral hearing loss from the age of 6 months and as a temporary measure in cases such as bilateral ear malformations, which will be addressed later in life surgically.
However it is worth noting that even in the case of a cochlear implant it is important for the prospective child to go through a pre-cochlear stage which should be done by applying hearing aids. This is because through the hearing aids the child will begin to familiarize with sounds and generally with the existence of a “foreign body” behind their ear.