TUESDAY, Feb. 17 (HealthDay News) -- Difficulty recognizing words in loud settings is a common concern for older people, and new research suggests the problem may involve more than hearing loss, but rather age-related structural changes in the brain.

"We found that a small portion of the brain's auditory cortex is closely related to word recognition, and that structural change in the volume of this area is associated with recognition problems in older patients," said study author Kelly C. Harris, an assistant professor in the department of otolaryngology head and neck surgery at the Medical University of South Carolina.

Harris is scheduled to present her preliminary findings Sunday at the 2009 Midwinter Meeting of the Association for Research in Otolaryngology, in Baltimore.

The National Institute on Aging estimates that about one-third of Americans between the ages of 65 and 74 experience hearing loss -- a number that rises to 50 percent among people 85 and older.

To gauge the role that age-related brain changes might play in hearing loss, the study authors conducted hearing exercises while using MRI to scan the brains of 18 younger adults between the ages of 19 and 39, and 18 older adults between the ages of 61 and 79.

While undergoing the scans, all the participants were tested on their ability to identify certain words, with some words filtered to reduce intelligibility. The researchers found that in "challenging listening conditions," the older adults were generally much worse at recognizing words than younger adults.

Even after accounting for the loss of high-frequency hearing that typically accompanies old age, the researchers found that the poorer performance among the older adults was linked to a reduction in the size of small portions of the auditory cortex, a section of gray matter in the brain that controls hearing.

This could ultimately explain how and why some hearing problems worsen with age.

Harris suggested that, with further research, the findings might improve rehabilitation efforts to help older people cope with particular hearing difficulties.