The Tomatis Method
In the 1950s, Dr. Alfred Tomatis developed the first listening training device using progressively filtered sound, specifically sounds rich in high frequencies, to address learning problems. Dr. Tomatis found that children with learning disabilities often have difficulty distinguishing between low- and high-pitched sound frequencies, and do not perceive high frequencies sounds well.
He also theorized that language problems could be caused by an inefficient pattern of dominance. Sounds captured by the right ear are directly transmitted to the language center in the left brain. On the other hand, sounds captured by the left ear go first to the right brain before being transmitted to the language center in the left brain; this more circuitous route is less efficient for listening to the sounds of language.
Dr. Tomatis developed a device to retrain the ear by switching constantly between two channels, one emphasizing low-pitched sounds and the other accentuating higher frequencies. The switching forces the ear to adjust continually to changing sounds.
Your child listens to electronically filtered recordings of Mozart, the mother's voice, and Gregorian chants through headphones that have a special bone conductor on the top. The listening exercises are gradually combined with active exercising using the voice to maintain learning. Through this training, your child essentially relearns the listening process.