Cutting-edge technology and hearing health awareness are instrumental in diagnosing infant hearing defects.

 While many audiologists and hearing instrument manufacturers focus on the needs of aging Baby Boomers, they are missing another segment of the market that, although smaller, is equally important—infants. According to information from the Alexander Graham Bell Association, hearing impairment is the most common birth defect in children, occurring in three out of 1,000 births.

Technology has made it possible to identify those children with hearing loss immediately after birth—instead of at 2 or 3 years of age, as was typical in the past—and do something about it from the start. This infant hearing testing—which is performed in a variety of ways—is a way to ensure proper cognitive development. “Hearing loss affects all areas of a baby’s development—social, emotional, speech, language, and cognition,” says Breena Scharrer, MA, CCC-A, FAAA, an audiologist and coordinator of the Early Hearing Detection and Intervention Program, Mott Children’s Hospital, University of Michigan, Ann Arbor. “We want to make sure we’re facilitating all those avenues to mitigate as much as we can the negative effects of the hearing loss.”

Mandatory Infant Testing
Though the Baby Boomer patients have the higher public profile, legislation in several states has made infant testing mandatory. In the states surveyed by Hearing Products Report, participation in and compliance with the government-mandated program has been nearly 100%.

And responding to the need, manufacturers, such as Vivosonic, Bio-Logic Systems Corporation, and Maico-Diagnostics, have developed testing equipment and have supported the efforts of hospitals, school systems, primary care physicians, and audiologists to test all newborn children for hearing loss.

There are several ways to test for hearing loss in children, including auditory brainstem response (ABR), otoacoustic emissions (OAE), acoustic immittance audiometry, and behavioral audiometry—none of which has been accepted as the best screening method. What has been set is the steps that clinicians need to follow to determine if an infant has normal hearing or needs additional help.

Check and Double Check
The Early Hearing Detection and Intervention Program at Mott Children’s Hospital was recently cited by the Alexander Graham Bell Association for its screening and follow-up programs. The program is a model of how screening should be handled.

Testing is performed with the permission of the parents using an automated brain response device. “We put electrodes on [the infants’] foreheads and behind their ears, and then we use a little probe in their ear canal to deliver the test stimulus, which is a very soft clicking sound. And if the ear hears, it generates electrical activity, which is picked up by the electrodes on the scalp,” says Scharrer. The child must be asleep in order to have the test, which is sometimes the biggest challenge facing clinicians. The Mott Children’s Hospital program has 12 locations, and has been in operation since 2001.

If the child passes, no additional follow-up is given. If the child fails the test, they are retested 2 weeks later. According to Scharrer, about 95% of the retested babies pass this second test. Failure of the first test usually is a result of birth material that is still lodged in the child’s ears.

Of the rescreened babies, about 1% are referred for full diagnostics, which could result in immediate treatment. “If we diagnose a baby at 3 weeks of age, then they’ll have hearing aids on by 5 or 6 weeks of age, which is critical to get them that early input,” says Scharrer.

Follow-up is not just left to the clinic. Early intervention specialists also visit the children in their home. “They teach the family communication strategies and get them any other assistive listening devices besides hearing aids that may be helpful,” says Scharrer. “Of course, the child is going to be seen by an ear, nose, and throat physician right away to see if there is anything that can be done to treat the hearing loss or perhaps they’re going to be a candidate for a cochlear implant. You can initiate treatment as soon as hearing loss is identified.”

The only patients who receive state-mandated hearing screening in Michigan are those on Medicaid. There are no private insurers in the state of Michigan that pay for the testing, says Scharrer. But even though the price of the screening has to be picked up by the parents, it has been very well received with parents of only five of the first 4,000 patients refusing the screening.

Universal infant hearing testing was first recommended by the National Institutes of Health in 1993. Currently, there are about 2,500 different programs in the United States.

In other states, the mandate is more all-encompassing. For instance, Florida requires that all birth facilities or hospitals that provide maternity and newborn care offer screenings on all newborns prior to discharge. The legislation covers home births as well. New York also has instituted universal infant hearing testing, covering all maternity hospitals and birthing centers. Other states, such as Kansas—with its swaths of rural farmland—require universal screening, but offers an exception. Hospitals that have fewer than 75 births a year over a 3-year period are exempt from the requirement, but must identify a facility or audiologist who can provide the testing.

In Florida, New York, and Kansas, the participation in testing has been high. In New York, 96% of facilities have complied with the 2001 legislation. In Florida, compliance has been even higher with a rate of 98%.

Like the Mott Hospital program, follow-up is a component of the mandated programs. In New York, it is recommended that rescreening be completed before discharge and, if not, then sometime shortly after. Those children who do not pass must be given a prescription, which includes a request that the results be returned to the birth hospital. In Kansas, children who do not pass must have a follow-up examination before 2 months of age. Florida has similar provisions with a requirement that results of the retest, including interpretation and recommendations, be placed in the child’s medical record within 24 hours of the test.

No matter the requirements, each of these states reports that the savings to the state and the health system are high. According to New York State Health Department officials, “The cost and positive predictive value of universal newborn hearing screening compare favorably with the cost and predictive value of screening for other congenital conditions. The cost of newborn hearing screening has been estimated as $17 to $33 per infant, and depends on a number of factors, including the type of technology used, number of births per hospital, and the qualifications of the personnel. Consequences of late identification of hearing loss include delayed speech and language development, and associated effects on social and emotional growth and academic achievement.”

The mandate to screen does not mean that hospitals, clinicians, or parents have no support from the state agencies. New York provides four brochures—in English, Spanish, French, Chinese, Russian, Bengali, and Urdu—on newborn hearing screening. In addition, the New York Department of Health holds training programs. Kansas has its Sound Beginnings program, which offers training and technical assistance for early interventionists, audiologists, other hearing health professionals, and parents. The state is also planning a family conference for September 2004. In addition to printed materials and training programs, the Florida Department of Health has a Web site, www.cms-kids.com, filled with information about hearing.

All this information and the potential for a positive diagnosis can be a bit overwhelming, but, says Scharrer, it is worth it to parents. “The parents have to go through the grieving period, but the blessing of finding [hearing loss] early is that they don’t have the regrets that they have missed all this precious time,” she says.

Infant screening is as much about awareness of the widespread incidence of hearing loss as it is about technology.

Hearing Wizards
Vivosonic, Maico-Diagnostics, and Bio-Logic Systems Corporation all have a presence in the testing market, so moving into the niche of testing babies was a natural extension of this. “We focus on objective tests. They are the only audiometric means in babies, but often can be very difficult to perform with conventional equipment,” says Yuri Sokolov, PhD, MBA, president and CEO of Toronto-based Vivosonic Inc. “Through innovative technological solutions, we make these tests more efficient clinically and economically. The users [of our equipment] tell us that they can test patients easier and faster, saving time and money. What benefits testing babies, which is very demanding and challenging, also benefits testing patients of other ages thus extends our market.”

David Adlin, national sales manager for Maico-Diagnostics, Eden Prairie, Minn, adds that the push for mandated testing of infants—making the need for equipment universal—contributed to making the move into this area a sound business decision.

Though the niche is strong, says Gabe Raviv, CEO of Bio-Logic Systems Corp, Mundelein, Ill, it is fairly static. “It is true today that the market in the United States, because 85% of all the babies in the market are screened, is not growing,” he says. Entering the market early has helped Bio-Logic, which has testing contracts with several large child-focused organizations, such as Boys Town and Special Olympics. The hearing division of the company is its fastest growing.

Though Maico, Vivosonic, and Bio-Logic are committed to hearing testing, each company’s screening device is a little different than its competitors’.

Maico’s infant testing device, the EroScan, is an OAE device, which measures the low-level sounds generated by the outer hair cells of the cochlea in response to an auditory stimulus. “With the handheld probe, an acoustic signal is presented, traveling through the ear canal to the outer cochlea. The hair cells are excited and emission is generated,” says Adlin. “This travels back to a microphone in the probe where the data is then calculated for the results—either PASS or REFER. Pass indicates normal OAEs, which correlates to normal hearing and normal cochlear function. Refer means the OAEs are not present and is suggestive of a possible hearing loss greater than 30 dB HL or an outer or middle ear disorder like otitis media. The test takes 10 to 30 seconds per ear, and using the remote probe, the infants can still move their heads and be more comfortable.”

The EroScan, according to Adlin, gives clinicians certain advantages over other systems. “Testing can be performed by a nurse or trained volunteers since the test results don’t require interpretation and no response or complex cooperation from the patient is necessary,” he says. “Infants can be squirming or even making noise and accurate testing is still possible. The equipment is thousands of dollars less than ABR equipment, which also provides testing that fulfills this screening need. The EroScan performs the testing at 2,000, 3,000, 4,000, and 5,000 Hz and prints the results on its thermal printer in about 3 seconds.”

When Bio-Logic entered the market 25 years ago, it did so with an ABR system, and has several screening products, including portable ones, and now a follow-up diagnosis device, the 2-year-old Master, which can complete the follow-up examination in 15 to 25 minutes. The company has a second testing system ABEAR, an ABR device, that is ideal for high-risk patients in intensive care units. The company’s Audex system—which it uses in its Special Olympics sessions—has the ability to operate in noisy environments.

Vivosonic’s portable VivoScan™ system performs screening and diagnostic OAE and diagnostic EP tests. The EP module includes the Amplitrode™ and VivoLink™ that solve several well known problems surrounding the use of evoked response audiometry, particularly noise from electromagnetic interference and physiologic sources. “The Amplitrode is a novel EP amplifier. It is very small, the size of a quarter, and sits directly on the ground electrode pad without any lead wire, while the other two leads are very short and shielded, which largely reduces electromagnetic interference,” says Sokolov. “The Amplitrode optimally pre-amplifies and pre-filters evoked potentials at the source, thus significantly reducing physiological noise too. As a result, the EP signal from the Amplitrode is less noisy than those obtained from conventional amplifiers. The VivoLink connects the Amplitrode and stimulating transducers with the VivoScan through wireless Bluetooth communication [technology] and provides the operator and the patient full freedom of movement.” In addition, the device monitors impedance mismatch between electrodes continuously thereby notifying the tester immediately if electrode-patient contact becomes poor.

As each company’s products illustrate, there is no single accepted way to test an infant’s hearing. Finding the best method to test infants is one of the roles of National Center for Hearing Assessment and Management (NCHAM).

Research Methods
A part of Utah State University, Logan, Utah, NCHAM works to improve the detection and provision of services to children with hearing loss. NCHAM provides no services or any screening itself. It does offer technical assistance to various organizations and has been involved in numerous research projects including ones trying to determine the best screening method for infants.

NCHAM was instrumental in proving that screening could be conducted on a large scale. According to Karl White, PhD, director of NCHAM, the organization’s research has found that there are still several areas in which screening programs need to improve. “We’re doing a fairly good job on babies before they leave the hospital—more than 90% of all the babies born are screened before they leave,” he says. “We still need to improve some of the quality of that screening. Most programs do an excellent job, but in every state we’ve looked at closely there are still a few hospitals struggling with poor coverage or very high referral rates that are unnecessary. Connecting screening to better diagnosis and intervention, we have a lot of work to do. I think we’re losing a lot of babies to follow-up. And I think another major issue is a severe shortage of pediatric audiologists. I think we have a [challenge] in terms of educating the medical field, the primary health care providers.”

No matter what the research shows is the best method, there is one thing that is clear, infant hearing testing is here to stay.

The Future
Bio-Logic, Vivosonic, and Maico are all committed to remaining in the infant testing niche. This is more than just an economic decision. There is the social good that motivates the companies. “The challenges in this market are education-related,” says Adlin. “Medical professionals who don’t specialize in hearing testing have many products and services vying for their attention. It’s easy, and makes sense, to place greater importance on more life-threatening illnesses. But if more people understood that hearing loss is one of the most common birth defects and affects a person’s ability to communicate, learn, develop socially—it would not go so often undiagnosed and untreated. So many more children could lead fuller lives. Most parents don’t notice a problem until the child is about 1 year old—and by then some of the effects can be irreversible. But it’s important to educate parents too, so that if newborn hearing screening is not provided for them initially, they can approach their pediatricians or primary physicians to perform the tests.”

Chris Wolski is associate editor of Hearing Products Report.