Many treatments and interventions in autism have focused on methods to reduce maladaptive behaviors and symptoms of related comorbidities such as seizures. By way of contrast there has been little research regarding some of the sensory problems observed in this condition. In spite of the limited rigorous research, a variety of interventions directed at reducing sound sensitivity and related auditory problems are currently used by practitioners and parents, with positive results reported in some cases.
Auditory integration training (AIT), was developed by French otolaryngologist Guy Berard and was based on the work of his predecessor, Alfred Tomatis. Dr. Berard originally developed his method of AIT to rehabilitate disorders of the auditory system, such as hearing loss or hearing distortion (hypersensitive, hyposensitive, or asymmetrical hearing). AIT uses filtered and modulated frequencies imbedded in pleasant music to help re-train the auditory system and normalize the way the brain processes information. It seems very likely that if a child with autism could hear and process sounds more accurately, he/she could understand and speak more accurately and clearly, thus improving many related areas such as social skills, emotional competence and relatedness, and social communication ability. The Berard AIT program is based on theory that the use of electronically modulated, and selectively filtered music retrains the ear and auditory system to work properly.
The standard Berard AIT protocol consists of two 30-minute sessions of listening each day within a 10 day period. The listening sessions are separated by a mandatory three-hour interval to allow a break from the auditory stimulation. Music is represented by a variety of light rock, reggae, and jazz, selected specifically to assure that it contains a wide range of frequencies from 20 Hz to 20 kHz. A filtering device called the Eareductor modulates the music. The processed music does not exceed an average output of 85 dB (safety limit imposed by the FCC). The Earducator/6F intermittently emphasizes low and high sound frequencies in the music (called gating or modulation). Children listen to the music through closed, high fidelity headphones while quietly listening without engagement in cognitive activities.
AIT has been reported to be beneficial in several conditions, including autism, dyslexia, ADHD, and hypersensitive hearing at certain frequencies. Of 28 research studies that evaluated physiological, behavioral, and cognitive changes in AIT recipients, 23 (82%) studies concluded that their data supported the efficacy of AIT, three (11%) claimed to have found no evidence of efficacy, and two (7%) report ambiguous, contradictory results. Among those were 13 studies on autism and 11 of them reported positive results and only 2 had mixed results (Edelson & Rimland, 2008). Review of theoretical models aimed to explain effects of AIT in children with ASD and other neurodevelopmental disorders can be found in Berard and Brockett (2011). Unfortunately, most studies to date using AIT were designed as open-clinical trials with no control groups for comparison.
More research on AIT is needed as they have the potential to advance knowledge about neurodevelopmental abnormalities underlying atypicality of auditory processing in ASD and could provide the basis for theory-guided educational training capable to substantially improving hearing, sound processing acuity, selective attention and other important functions thought to be compromised in children with autism.