Like so many parents, Christine Ingemi of Amherst, N.H., got tired of constantly telling her four children, ages 5 to 11, to turn down the volume on their iPods. It would be so loud sometimes, I could hear the music through the headphones, she said. However, music is important to her and her family, she said, so she searched for a way to limit the noise without banning her children from their iPods.

Volume-Limiting Earbuds: Safer Sound for iPod Headbangers