Some noisy toys may cause hearing damage if not used properly, researchers in U.S. said on Thursday.

They found that the sound level of more than a third of the 17 musical and noise-making toys they examined reached 100 decibels or more -- equivalent to the sound of a chain saw or subway train.

"For some of the louder toys, if a child were to take that and hold it out against their ear for a matter of minutes, they could potentially do some long-term hearing damage," said Jeff Carroll, of the University of California, Irvine, who headed the research team.

"What we're trying to push here is not that the toys themselves are bad or shouldn't be purchased or taken off the market or anything like that. It's more education and supervising your child and making sure they understand what's safe and what's not," said Carroll.

He added that any of the toys, which were tested at a short distance from a speaker, should be not be listened to at full volume closer than arm's length from a child.

The close proximity makes toys such as singing dolls or teddy bears, which children tend to play with closer to their face, more risky than wailing police cars or fire trucks.

(Agencies via Xinhua News Agency December 7, 2007)