Hearing Tests for your Child

As every parent knows, sometimes children hear, but they don't listen. Some parents, on the other hand, suspect that their children try to listen — but don't hear as well as they should.

These suspicions often remain unconfirmed until the child is 24 to 30 months old. By that age, the child's difficulty in speaking and understanding is apparent. And children whose hearing problems have gone undetected until they are that age may have impaired language development and, down the road, less academic success.

Testing for all infants

Such children now can be identified and helped at a much earlier age, according to Martin Robinette, Ph.D., audiologist at Mayo Clinic, Scottsdale, Ariz. "In most cases, the practice has been to test only infants who fall into high-risk categories," says Dr. Robinette. "These include those with low birth weight, deafness in the family, premature birth or an infant in intensive care. The problem is that half the children who end up with permanent hearing loss don't fall into any of these high-risk categories. So their hearing loss sometimes isn't recognized until they are older and are having language problems."

Test makes screening easier

A hearing test for infants has long been available, but it involved placing electrodes on the baby's head to measure brain activity. It was time-consuming and expensive.

But a simpler screening test has been developed. The otoacoustic emissions test (OAE) is the invention of a British physicist, David Kemp. He discovered that the human ear — when it's working correctly — will echo a series of clicks sounded in the ear canal. These extremely faint echoes are analyzed by a computer and interpreted by an audiologist.

The test is easy to conduct. A small device resembling an earplug is placed in the ear canal. The person being tested hears only a series of rapid clicks or tones. The results appear as a jagged bright blue line on a computer graph.

The test also is quick. For an infant, the test takes from 15 seconds to 2 minutes for each ear. And it's fairly inexpensive.

Testing the test

"The professional organizations representing language pathologists, otolaryngologists, pediatricians and audiologists have endorsed the idea of screening all infants," says Dr. Robinette. He expects screening every newborn to become the standard of care as more states and hospitals make universal hearing tests a priority.

Universal infant screening is already mandatory in several states, and more are beginning to require the testing. Hundreds of hospitals throughout the country are electing to screen every newborn.

"About 4 percent to 8 percent of babies do not pass the initial screening and need to be re-screened either just before leaving the hospital or at the first well-baby checkup," says Dr. Robinette.

Eighty-five percent of those who are re-screened will pass, leaving about 1 percent of infants who need additional evaluation. If permanent hearing loss is confirmed, these children can be fitted with hearing aids at ages as young as 2 to 3 months. They then can begin receiving language enrichment stimulation.