Children who are undernourished during preschool years are more likely to suffer from hearing impairment later in life, a study has found.

Hearing loss is the fourth leading cause of disability worldwide, and an estimated 80 per cent of affected individuals live in low and middle-income countries, researchers said.

The study, published in the American Journal of Clinical Nutrition, analysed the relationship between the hearing of more than 2,200 young adults and their nutritional levels as children 16 years earlier.

"Our findings should help elevate hearing loss as a still-neglected public health burden, and one that nutrition interventions in early childhood might help prevent," said Keith West from the Johns Hopkins University Bloomberg School of Public Health in the US.

Results of the auditory tests show that young adults who were stunted in childhood were nearly twice as likely to show signs of hearing loss.

Stunting, or being too short for one's age, is a chronic condition of undernourishment that often starts before birth, which is a critical time for the development of auditory function.

The researchers suspect that impeded inner ear development caused by undernutrition, especially in the womb, may contribute to the increased risk of hearing loss found in the study.

The participants who were too thin as children were also at a two-fold increase of hearing loss, the researchers said.

Being too thin for one's age is typically caused by acute malnutrition, defined as shorter, more severe periods of undernutrition.

Acute malnutrition raises children's susceptibility to infections, including in the ear. Repeated ear infections can lead to hearing loss.