EVANSTON, Ill. -- A new, easy-to-use diagnostic tool that can quickly identify a sizeable subset of learning disabled children is now commercially available.

That's good news for youngsters aged 8 to 12 who, once identified, can receive auditory training that can improve their academic learning.

"Learning disabilities are believed to affect nearly one in 10 children, but their causes are difficult to pinpoint," says Nina Kraus, director of Northwestern University's Auditory Neuroscience Laboratory. She and Northwestern researchers Trent Nicol and Steven Zecker have found that a third of the 1,000-plus children they have tested show a dysfunction in the way the brainstem encodes basic sounds of speech.

BioMAP (Biological Marker of Auditory Processing) is based on more than a decade of neuroscience research at Northwestern University. It is expected to become one of the most important resources for learning disabilities specialists trying to identify appropriate treatments for children with dyslexia and other language-based learning disabilities. Bio-logic Systems Corp., a Natus company, of Mundelein, Ill., holds an exclusive license from the University for the technology.

"The beauty of BioMAP as a diagnostic tool is that it does not require a child to follow directions or perform an assigned task," says Kraus. "Instead, it objectively measures whether a child's nervous system is able to accurately translate sounds into brain waves." If it can't, the affected child will have difficulty discriminating between speech sounds. And that difficulty at the most fundamental level complicates a wide range of learning activities, including reading and writing, Kraus finds.

Getting objective measures from BioMAP software is simple. "All a child needs to do is stay awake and sit quietly for 20 to 30 minutes," says Kraus, Northwestern's Hugh Knowles Professor of Communication Sciences, Neurobiology and Otolaryngology.