Hearing impairment is the most common developmental defect at birth, and the prevalence of congenital hearing loss in newborns is about 1-3 per 1,000; however, the prevalence of hearing loss in school-aged children is much higher than the rate at birth. Data show that the percentage of preschoolers with hearing impairment can be as high as 19.5%, which includes permanent hearing loss and conductive hearing loss.
In addition to congenital hearing impairment, new hearing impairments can occur at various stages of development, and reports vary widely between regions and populations. preschool children between the ages of 3 and 6 years are at an important time when they are learning and acquiring language and speech, and even mild hearing loss can significantly affect their behavior, development, learning, and health. Therefore, it is important to conduct hearing screening for preschoolers to identify children with permanent hearing impairment as early as possible, to provide early diagnosis and intervention, and to reduce the adverse effects caused by hearing loss.
At present, some kindergartens in Shanghai have been conducting hearing screening for preschool children on a regular basis, parents may have the following questions, we are here to answer them.
If our child passes the newborn hearing screening, do we still need to do the preschool hearing screening?
Permanent hearing loss is not always detected early through newborn hearing screening programs for three reasons.
(1) The newborn hearing screening program uses screening equipment that is designed to detect hearing loss with an average hearing threshold of 30 to 40 dB HL or worse, and is likely to miss mild hearing loss;
(2) Newborn hearing screening does not detect hearing impairment that is not present at birth and deafness that occurs after birth – late onset hearing loss;
(3) Some of the children who do not pass the newborn hearing screening do not receive referrals, and therefore this population is not evaluated for detailed hearing and effective intervention.
Delayed hearing loss in children is generally considered to be hearing loss that occurs after the perinatal period and refers to three main conditions.
① Delayed onset hearing loss, where hearing is normal during the perinatal period and specific harmful conditions around birth cause damage to the inner ear, resulting in hearing loss that begins over time at some later time, such as intrauterine congenital infection, severe asphyxia, continuous mechanical ventilation, and hyperbilirubinemia.
(ii) Progressive hearing loss, normal hearing performance at birth, followed by hearing loss at different rates of progression, frequency and severity associated with genetics, neurodegenerative disease or other factors after birth.
Acquired hearing loss is caused by direct or indirect action of acquired factors on the inner ear, such as meningitis, ototoxic drugs and acoustic damage.
In addition, in addition to permanent hearing loss, a significant proportion of preschoolers with hearing impairment have conductive hearing loss. The conductive hearing impairment found in these cases can partially recover on its own within about 2-3 months, but some patients may develop persistent or recurrent otitis media and require early treatment. If these children with hearing abnormalities are diagnosed early, they can receive early treatment and effective intervention to improve their language, socialization, learning, and long-term quality of life.
Why do preschoolers need to be screened every school year?
Hearing impairment in preschoolers can be congenital or delayed, and both can be caused by genetic and non-genetic factors. The prevalence of delayed hearing loss increases progressively with age, with approximately 30% of permanent hearing impairments being delayed. Delayed hearing loss is generally used to define hearing loss that does not manifest at birth and occurs gradually during postnatal growth and development. For preschool and school-age children between the ages of 3 and 15, the proportion of permanent hearing loss that is delayed hearing loss varies from approximately 11% to 50%.
There is evidence that the incidence of moderate and greater bilateral permanent hearing loss tends to increase before the age of 10 years in children, including meningitis, measles and other causes of acquired hearing loss in children; progressive development of bilateral and unilateral hearing loss; and delayed hearing impairment associated with maternal pregnancy and perinatal infections or due to genetic factors. Some patients with mild hearing loss who are missed by newborn hearing screening and children referred for missed visits may not be easily detected by parental observation.
Hearing loss in preschool children between the ages of 3 and 6 years is an important time for learning and acquiring language and speech, and hearing loss during this period can seriously affect a child’s ability to communicate and learn. Unilateral hearing loss has been found to adversely affect speech and language development, learning ability, and long-term development, and even mild hearing loss (26-40 dBHL) can significantly affect children’s behavior and performance in school. Therefore, regular hearing screenings during the preschool years can identify emerging hearing problems and provide early diagnosis and intervention.
Third, our children do not say they cannot hear sounds in their lives, could there be a hearing problem?
The behavioral effects of hearing loss in preschoolers are usually not easily detectable, similar to lack of attention, learning disabilities, language processing problems, and cognitive backwardness. Children with mild, and in some cases moderate, hearing loss in preschoolers may lack the typical presentation. If a child has difficulty concentrating, answering questions, is easily fatigued, or has poor academic performance, it may be due to hearing loss.
For younger children under the age of 4, the manifestations of hearing loss are less specific because they are less able to express themselves in daily life and are less likely to express physical abnormalities to their parents, yet the presence of hearing abnormalities in younger children can have a more significant and potentially long-term impact on the child’s life, development, and learning. The most common behavioral manifestations in preschoolers may include the following: difficulty hearing verbal and other auditory information; frequent requests for repetition; fatigue when listening; giving inappropriate responses to simple questions; acting distant from peers; poor reading skills;
Weak written and oral skills; easily frustrated, etc. Parents and teachers usually do not easily associate these phenomena with hearing problems, but the delay in diagnosis and treatment, whether permanent or fluctuating hearing loss, or even very mild hearing loss, can make it difficult for school-age children to receive language properly, especially in noisy and empty classrooms and when the speaker is a certain distance away.
Studies have found that children with very mild hearing loss are at higher risk than normal children for.
1) Learning difficulties, requiring repetition;
2) speech and language deficits, with communication difficulties; 3) difficulties with social-emotional control, poor self-esteem, lack of spirit, etc.
Therefore, hearing screening for preschool children is necessary for early detection of hearing impairment and early intervention in school-age children.