Other models of AIT exist, but the Berard method remains the most popular. Berard developed the AudioKinetron and the Earducator(TM), devices that deliver music at specific frequencies through headphones. The regimen includes two, 30-minute sessions, three hours apart each day over the course of 10 days. A one- or two-day break may be taken after the first five days. Candidates must be at least 3 years of age and may have a diagnosis of autism, pervasive developmental disorder (PDD), ADHD, central auditory processing disorder, or other learning disabilities or processing disorders.