Noise Harmful to Babies
EXPOSURE TO NOISE DURING THE FIRST MONTHS OF LIFE could affect a child's hearing and cause learning problems, says medical student Edward Chang, of the University of San Francisco.
He and his consultant, neuroscientist Michael Merzenich, exposed newborn rats to continuous white noise for up to three months. They then anesthetized the animals and studied their brains. The rats showed a significant delay compared to the control group.
"The basic shape of their auditory cortex developed more slowly, and the response properties of individual neurons were also delayed," says Chang.
In general, the brains of rats exposed to noise matured up to four times more slowly than normal.
In many ways, the development of human hearing resembles that of rats. That's why the researchers are concerned about children growing up in noisy environments, such as near airports or busy highways.
"In humans, developmental delay can be severe. Many children with learning disabilities eventually catch up, but they do it more slowly," says Chang.
He and Merzenich are trying to identify children who, due to genetics or physiology, are especially susceptible to noise-related hearing loss. "Then we could recommend if a child needs a special enriched environment.
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