Doctors have been doing cochlear implants on infants for years, said Dr. Daniel Choo, the assistant professor of otology/neurotology leading the study.

Until now, however, doctors haven't been able to tell if that procedure would help a very young child until after the child has undergone the surgery.

That's because children under 12 months can't speak or communicate a great deal, Choo said. "We just don't have a lot of assessment tools to determine if a child is doing OK with hearing aids."

In some children, even if the outer and middle ear successfully can collect sound pressure signals from the outside, the inner-ear structure called the cochlea can't convert that information into an electrical signal that nerves can carry to the brain.

The treatment in such cases is the cochlear implant, which is used to manage severe to profound sensorineural hearing loss, or nerve deafness.

Functional magnetic resonance imaging -- fMRI -- can help, Choo said.

"The functional MRI tells what parts of the brain are working hard," he says.

A portion of the brain that is active needs more oxygen and the body, therefore sends more blood there. The fMRI, a program that can be used with regular MRI technology, tracks the blood flow and oxygen going to the two main centers of the brain that decode language, Choo says. In the current study, children in the MRI scanner first hear a series of music-like tones to determine if there are changes in the brain to indicate the primary auditory cortex is processing changes in pitch. Children then hear a story, and doctors examine results to determine if the brain's language centers are trying to make sense of words.

The tests do not require additional time in MRI scanners for children. They are performed during regular scans that children with hearing problems undergo as part of the examination of inner-ear anatomy.

The five-year study of the fMRI technology is being funded by a National Institutes of Health grant of nearly $3 million. It will involve 90 patients, including 30 infants with normal hearing in a control group.

The timing of the study is significant because a state law that went into effect in June requires universal neonatal screening for hearing loss. The law's rationale is to begin assessment and treatment earlier to prevent long-term language-learning delays, Choo said.

Before the law kicked in, Children's was seeing 175 to 200 children with newly diagnosed sensorineural hearing loss every year.

Now, "our audiologists are seeing many more than that as a result of the newborn hearing screening," Choo said.

By Roy Wood