Non-genetic Factors Affecting Hearing Development

Abstract

The developing ear is sensitive to chemical and physical changes in its environment. Over the last ten years, many experimental studies have shown that the young ear is more susceptible to noise exposure and to the ototoxic effects of certain drugs. Other factors such as thyroid deficiency, viral infections and hyperbilirubinemia are recognized causes of hearing loss in the human infant and are beginning to be studied experimentally. These experiments are important for determining sensitive (“critical”) periods during which the young ear is more susceptible to environmental factors and may lead to a better understanding of the causes of deafness in children.