Early Identification Of Hearing Loss And The Physician's Role

Mary Elizabeth Givens, M.A./CCC-A and Angelique N. Williams, M.S./CCC-A
Mary Elizabeth Givens, M.A./CCC-A and Angelique N. Williams, M.S./CCC-A are with the Early Intervention Program, Pediatric Hearing Program at the University Of Florida Health Science Center/Jacksonville.

There is widespread acceptance of the need to identify hearing loss at an early age. The rationale behind this thinking is based on the existing research, which indicates that of infants in this country with hearing loss, most go undetected until approximately 2.5 years of age. There is general agreement that the earlier hearing impairment is detected, the greater the potential of maximizing speech and language skills. Ideally, all children should be screened for hearing impairment prior to hospital discharge, as it is estimated that 50% of children born with a hearing impairment are missed using a risk-based screening only. In the Jacksonville area there are both risk-based and universal screening programs; however, the overwhelming trend is moving towards universal hearing screening. Moreover, 20 - 30% of all children with hearing loss develop that loss in early childhood. Therefore, the child's physician must take an active role in referring for formal hearing assessments. (Table 1)

Table 1. Indicators Utilized By Risk Based Hearing Screening Programs
Family history of hereditary childhood sensorineural hearing loss; In utero infection, such as cytomegalovirus, rubella, syphilis, herpes, and toxoplasmosis; Craniofacial anomalies, including those with morphological abnormalities of the pinna and ear canal; Birth weight less than 1,500 grams (3.3 lbs.); Hyperbilirubinemia at a serum level requiring exchange transfusion;	Ototoxic medications, including but not limited to the aminoglycosides, used in multiple courses or in combination with loop diuretics; Bacterial meningitis; Apgar scores of 0-4 at 1 minute or 0-6 minutes at 5 minutes; Mechanical ventilation lasting 5 days or longer; Stigmata or other findings associated with a syndrome and/or conductive hearing loss.
Source: Joint Committee on Infant Hearing - 1994 Position Statement.

Importance Of Early Identification Of Hearing Loss

It is widely recognized that the critical learning period for speech and language development is birth through three years of age. If a child has a hearing loss during this critical time period, there can be detrimental effects involving speech and language development. An infant or child with hearing impairment is not able to receive adequate auditory and linguistic information needed to acquire normal speech and language skills. Delays in developing speech and language skills can also have an adverse effect on social development. Lack of receiving auditory information due to hearing loss, can also affect neural development of the auditory pathways due to auditory deprivation. The earlier a child with hearing impairment is diagnosed, the sooner early intervention can begin to help limit and or prevent the negative effects of hearing impairment.

A few researchers have examined the benefits of early diagnosis of hearing loss and early intervention. Yoshinga, Sedey, Coulter, and Mehl examined 150 deaf and hard of hearing children. The ages ranged from 1 year 1 month to 3 years 0 months. The researchers found that the group who was diagnosed before 6 months of age exhibited significantly better receptive and expressive language skills than the group who had been diagnosed after 6 months of age. In addition, for normal cognitive development, the finding was evident across all test ages, communications modes, degrees of hearing loss, and socioeconomic strata. Moreover, the finding was independent of gender, minority status, and the presence or absence of additional disabilities.

Robinshaw conducted a longitudinal study to examine the impact of early intervention in the hearing impaired children. Children with severe and profound hearing impairments who were fitted with amplification prior to six months of age displayed communicative and linguistic skills very similar to those of their normally hearing peers. He further concluded that a delay in the fitting of amplification for as little as 3 to 6 months was enough to cause a significant delay in speech and language acquisition.

The two studies discussed above clearly demonstrate the importance and advantages of early diagnosis and intervention of hearing impairment. Physicians' role in this early diagnosis is very important as they have the means to evaluate a child on a regular basis for developmental milestones, and can make prompt referrals for hearing testing as appropriate.

Role Of The Practitioner

It is the role of the practitioner to be able to recognize when to refer a child for a formal hearing test. A formal audiologic evaluation performed by a certified audiologist is the best and most appropriate means to assess a child's hearing sensitivity and to rule out hearing loss. Hearing impaired children can "pass" typical hearing screenings such as playing noisemakers and clapping hands. Current technology allows for hearing testing to be performed as young as the first days of life, therefore a child can be referred for a formal hearing test at any age.

Due to the current trend towards universal hearing screening, physicians may wish to consider referring their infant patients for a hearing test if the infant did not receive an appropriate hearing screening in the hospital. An appropriate screening would be considered testing via auditory brainstem response or otoacoustic emissions. The Joint Committee on Infant Hearing recommends that hearing impaired children be identified by 3 months of age and intervention be in place by 6 months of age.

The National Institutes of Health Consensus Development Conference Statement on the Early Identification of Hearing Impairment in Infants and Young Children and the Joint Committee on Infant Hearing are in agreement as to when a child should be referred for formal hearing testing. NIH recommends that parental concern about a child's hearing or speech/language development at any age is enough reason for a prompt referral for a formal hearing test. Physicians should also refer promptly for a hearing evaluation if a child does not meet appropriate language milestones especially during the first 18 months. In addition, if a child acquires an auditory risk factor in early childhood, they should be referred for a formal hearing test. This includes middle ear problems. Although middle ear problems do not typically cause permanent hearing loss, it is important to refer a child who has middle ear problems for a hearing test, as middle ear problems can cause temporary hearing loss. Table 2 lists referral recommendations presented by the Joint Committee on Infant hearing which also includes points discussed by NIH.

Table 2. Indicators Associated With Sensorineural And/Or Conductive Hearing Loss

Parent/caregiver concern regarding hearing, speech, language and/or developmental delay
Bacterial meningitis and other infections associated with sensorineural hearing loss
Head trauma associated with loss of consciousness or skull fracture
Stigmata or other findings associated with a syndrome known to include a sensorineural and/or conductive loss
Ototoxic medications, including but not limited to chemotherapeutic agents or aminoglycosides, used in multiple courses or in combination with loop diuretics
Recurrent or persistent otitis media with effusion for at least three months.

Source: Joint Committee on Infant Hearing 1994 Position Statement

Additional reasons for referral for formal hearing testing include speech disorders, learning disabilities, developmental delays, autism, and attention deficit disorder. Max Stanley Chartrand, PhD., recently discussed auditory deprivation and hearing loss in children and its effects. Children with hearing loss may exhibit behaviors that can mimic these sorts of conditions.

Summary

Communication is the cornerstone of today's society. The focus of early intervention as it pertains to communication is to identify and intervene in instances where there is a barrier to language acquisition. There is a major improvement in the communication skills of hearing-impaired children identified prior to six months of age as opposed to hearing-impaired children identified later. It is often the case that the primary care physician is the first individual contacted when a problem is suspected. An audiologist can perform formal hearing testing on a child of any age. There is never a time that is considered to be "too early". Whenever there is a concern with the speech, language, or hearing abilities of a child of any age, formal hearing testing can easily rule out or confirm a problem in that area and provide an opportunity to begin the appropriate services for that child.

REFERENCES

Early Identification of Hearing Impairment in Infants and Young Children. NIH Consensus Statement Online 1993 Mar 1-3 [cited 1999 November 4]; 11(1): 1-24.
American Speech-Language Association (December 1994). Joint Committee on Infant Hearing 1994 Position Statement. Asha, 36, pp. 38-41.
Yoshinaga-Itano C, Sedey AL, Coulter DK, Mehl AL. Language of early and later-identified children with hearing loss. Pediatrics. 1998; 102: 1161-1171.
Robinshaw HM. Early intervention for hearing impairment: differences in the timing of communicative and linguistic development. British Journal of Audiology. 1995; 29: 315-334.
Chartrand MS. Auditory sensory deprivation in children and the increased role for dispensing professionals. The Hearing Review. 1996; 3: 8-15.