Doctors' orders: A hearing test for every newborn

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Every child born in Canada should be screened for hearing loss shortly after birth, Canada's baby doctors say.

In a position statement being issued Monday, the Canadian Paediatric Society is calling on all provinces to implement universal newborn hearing screening, saying that testing and early intervention prevents severe and costly developmental delays.

"Virtually every developed country has a screening program. It's shameful that Canada doesn't," Dr. Hema Patel, a staff pediatrician at Montreal Children's Hospital and lead author of the statement, said in an interview.

Only Ontario and British Columbia have universal programs, and Quebec has announced plans to create one. Other provinces tend only to test babies at high risk of hearing loss, such as preemies and those suffering serious infections like meningitis.

The CPS said a "comprehensive and linked system of screening, diagnosis and intervention" is needed and because health is a provincial responsibility, the group called on the provinces to unite their efforts to create a national program.

Hearing loss is one of the most common congenital disorders, affecting about five in every 1,000 newborns, but about half of those affected have no obvious risk factors.

"We had no clue our son had something wrong with his hearing," said Jennifer Beer, a Toronto mother.

Her son Harry was tested by the midwife shortly after birth and then referred to a public health nurse and an audiologist for further testing.

By three months, he was diagnosed with bilateral moderately severe hearing loss and fitted with hearing aids. Harry, now aged four, has normal linguistic skills and he has also learned American Sign Language at his preschool.

"I can't imagine what life would have been like if he hadn't been screened," Ms. Beer said. "It wasn't all sunshine and daisies but we got an early diagnosis and Harry got the help he needed."

Dr. Patel said early diagnosis of hearing loss is essential so that a child can acquire language skills - either spoken or ASL. But, where there is no universal screening, children tend not to be diagnosed before age two - when toddlers generally start speaking - and often not until they attend school.

"When there is hearing loss, parts of the brain don't develop so there is a profound, life-long effect," Dr. Patel said.

The principal one is difficulty learning, and that is costly. A Quebec study estimated that a universal hearing program would result in an annual savings of $1.7-million in that province alone because special education classes are much more costly than treating hearing loss - $17,904 annually for a hard-of-hearing student compared with $4,808 for a hearing student.

Rex Banks, chief audiologist at the Canadian Hearing Society, said the group is also strongly supportive of universal screening.

"Hearing loss is a lot more common than people realize," he said. "The good news is that we have really good treatments now."

There are a variety of types and degrees of hearing loss but, generally speaking, it is measured in decibels. Children with mild hearing impairment do not hear sounds below 20 to 40 decibels, while in those with profound hearing loss it is above 80 decibels. To give a sense of what that means, consider that the hum of a refrigerator is about 30 decibels and vacuum cleaner about 80 decibels.

For mild and moderate hearing loss, hearing aids are the treatment of choice. Hearing aids have become much more sophisticated in recent years and they can bolster specific pitches. Cochlear implants are an option for some children if their hearing loss is due to lack of sensory hair cells in the cochlea. In rare cases, hearing loss can be restored by surgical intervention that repairs structural damage to the ear. Profound hearing loss - deafness - is not reversible.

Mr. Banks said it is important that American Sign Language be taught early to children who are deaf and hard-of-hearing.

"The key to a good outcome is early language acquisition," he said. "And children can actually sign before they speak verbally."

TESTING A BABY'S HEARING

Hearing was traditionally tested with crude methods such as ringing a bell or tooting a horn to see if a newborn reacted. But those tests were notoriously inaccurate because it was impossible to know if an infant was responding (or not) to the sounds or the visual or tactile clues.

In universal screening programs, babies undergo two-step testing that is non-invasive and can be done shortly after birth.

In the otoacoustic emission (OAE) test, a probe is placed outside the ear. It sends tones into the ear and elicits an echo. A lack of echo indicates an absence of sensory hair cells on the cochlea and hearing loss.

In the automated auditory brainstem response (AABR) test, three electrodes are taped on the baby's head and the child is fitted with small headphones. Clicking sounds are sent into the auditory pathway and the response generates waves on a printout that indicate hearing loss.

Depending on the degree of hearing impairment, children can be fitted with hearing aids, they can get cochlear implants and they can be taught American Sign Language.