A set of hearing aids costs anywhere from $800 to $3,500. The average is $2,200, according to an industry study sponsored by Knowles Electronics. For children, most hearing aids are not covered by insurance and can run between $1,000 and $3,000 a set. They must be changed every few years as children grow. Batteries can add about $600 a month to that amount because they must be switched every two to three days.