Screening parameters for infants and children
The US Preventive Services Task Force (USPSTF) recommends universal newborn hearing screening,23 but this does not always happen. That’s why it’s important to ask all new parents whether their baby underwent hearing screening shortly after birth. If the answer is No (or they’re not sure), you may want to order it at this time.
Infants at increased risk for hearing loss—those who spent >2 days on a neonatal intensive care unit; have a congenital syndrome, family history of hereditary childhood sensorineural hearing loss, or craniofacial abnormalities; or were exposed to certain intrauterine infections—should be screened again at 24 to 30 months of age.23 Those with positive results on a newborn hearing screen require repeat screening within 3 months.24,25 If the repeat screen is also positive, a full audiologic evaluation is necessary.
Testing newborns. The most common methods of screening newborns for hearing loss are otoacoustic emissions (OAE) and automated auditory brainstem response (AABR). The average age of detection of congenital hearing loss prior to the availability of these tests was 2 to 3 years. Earlier detection is associated with better developmental outcomes.26
OAE assesses cochlear integrity and measures outer hair cell function. AABR assesses auditory function from the eighth nerve through the auditory brainstem.
Testing toddlers and older children. Any child exhibiting signs of possible hearing loss, such as learning disabilities or speech delay, should be referred for audiometric testing, as should those who have had recurrent otitis media. Tympanograms can be used to diagnose conductive hearing loss, which often results from middle ear effusion. A parent’s expression of concern about a child’s hearing also warrants a referral, as parents can be 12 months ahead of physicians in identifying hearing loss.27
“Play audiometry,” a behavioral test of auditory thresholds in response to speech and frequency-specific stimuli, is commonly used for children between the ages of 2 and 4 years. In this test, the child is instructed to place a block into a box whenever he or she hears a sound.
Children >4 years are typically tested with conventional audiometry, and instructed to raise their hand in response to speech and frequency-specific stimuli. This technique may also be used in adolescents.
Consults, resources required after diagnosis
All children diagnosed with hearing loss after an audiologic evaluation require consultation with specialists in otolaryngology, ophthalmology, and genetics. They should also be offered special educational services, beginning with early intervention and continuing with appropriate monitoring and support throughout the school years. In addition, their parents should be given contact information for hearing loss resources ( TABLE 3). Adolescents and young adults with any degree of hearing loss should also receive counseling about noise exposure.28,29 We’ll review treatment options for hearing-impaired patients of all ages in a bit.
TABLE 3
Hearing loss resources for parents and patients
| Resource | What it offers |
|---|---|
| American Speech-Language-Hearing Association (ASHA) (www.asha.org) | Information about hearing loss in people of all ages |
| Beginnings for Parents of Children Who Are Deaf or Hard of Hearing (www.ncbegin.org) | Communication options for children with hearing loss |
| Better Hearing Institute (www.betterhearing.org) | Resources related to hearing loss for health care providers and patients |
| My Baby’s Hearing (www.babyhearing.org) | Information about newborn screening |
| National Institute on Deafness and Other Communication Disorders (www.nidcd.nih.gov ) | Information about hearing loss for the general public and health care providers |
In adults, most hearing loss is age-related
Advancing age is the single most important (and nonmodifiable) risk factor for hearing loss among older adults. Physiologic changes, including cerumen buildup, tympanic membrane thickening, degeneration of middle ear auditory structures, and decreased central auditory processing all may contribute to presbycusis—age-related sensorineural hearing impairment.30 High-frequency hearing loss is characteristic of presbycusis, and since consonants are high-frequency sounds, patients with this type of hearing loss often complain that they’re unable to understand speech.
Conductive hearing loss may be caused by cerumen buildup, foreign bodies, otosclerosis, cholesteatoma, or tympanic membrane perforation—all of which may be treatable. Potentially modifiable risk factors for hearing loss include smoking, diabetes, exposure to ototoxic medications, and occupational noise, as well as cerumen buildup.17
Maintain an index of suspicion
The most important factor in diagnosing hearing loss in older adults is simply remembering to screen. Elderly patients should be evaluated for hearing loss during their initial visit, and once a year thereafter.31 But all too often, that doesn’t happen. One study found that only 18% of patients between the ages of 65 and 74 years and 22% of patients ages 75 and older had undergone screening for hearing loss during their most recent physical examination.4