For most kids, the static electricity that builds up as they go down playground slides does little more than make their hair stand on end. But for thousands of hearing-impaired children, static can shut down their cochlear implants in an instant.

To try to help kids with implants enjoy slides, a group of Missouri researchers is studying just how much static electricity can build up on plastic playground slides as part of an attempt to find a solution to the cochlear conundrum.

It won't come too soon for Mary McGinnis, director of teacher education at the John Tracy Clinic, which serves hearing-impaired children in Los Angeles. "This has been the bane of my existence," said McGinnis, who's seen several cases of implants fried by static electricity.

An estimated 15,000 American children have cochlear implants, which convert sound into electrical impulses that the brain can detect.

Static electricity has been a problem for the implants since they first became available in the mid-1980s, McGinnis said. One of the first children to have an implant, she said, erased its memory by simply pulling a sweater over her head, and had to have the device replaced.

New generations of implants are less susceptible to static and typically don't need to be re-implanted after getting zapped. But playground slides and other sources of heavy static (like balloons) can still zap an implant and require it to be reprogrammed, which costs up to $1,000. The child, meanwhile, must go hours or days without being able to hear.

Armed with a $25,000 federal grant, researchers launched a study of exactly how much static electricity is created when a child goes down a slide. They filed their report with the United States Access Board in March.

By hooking sensors to children as they slid down slides in St. Louis and Tucson, Arizona, the scientists found that children easily built up 25,000 volts of electricity, the limit of the measuring devices.

"That's a pretty good lightning bolt," said study lead author Bob Morley, an associate professor of electrical and systems engineering at Washington University.

Plastic slides are such a strong generator of static because large parts of the body come in contact with the surface area, causing electrons to be rubbed free and cling to the kids, Morley said.

What to do? One idea is to coat the slides with an antistatic material. A St. Louis company called Crosslink is developing an antistatic coating for the canopies of Navy planes and has offered to look into whether its product might work for slides, too.

The coating contains polymers that conduct electricity and dissipate any charge, "never really generating the potential for a spark," said Patrick Kinlen, Crosslink's chief technology officer, who thinks the product could be used on slides at an affordable cost.

For the time being, however, children with cochlear implants should stay away from plastic playground slides. (Metal slides don't pose a great risk – at least one playground designed for the disabled has installed them to protect implant-wearing kids – but they get hotter in the summer.)

Staying away from slides is "very hard for a child," said McGinnis, the trainer of teachers for hard-of-hearing kids. "But it's probably even harder for a parent. All the parents I know want their children to look and be like all the other children."