Filtration/gating (F/G) techniques have been honed in Tomatis clinics worldwide. No discussion of this methodology can take place without humble acknowledgement of Dr. Alfred Tomatis, considered by many to be "the Einstein of the ear."
By gradually gating and filtering out the lower range of music (sometimes up to 8000 Hz), and then adding the frequencies back in, a retraining of the auditory processing system occurs. The effects of filtration and gating are felt on a psychological, neurodevelopmental, and physical level. The application of sound stimulation has been effective in the remediation of many neurodevelopmental issues. Children and adults with learning/attention difficulties, developmental delays, auditory processing problems, sensory integration and perceptual challenges have experienced profound improvement.
SOUND STIMULATION WITH FILTRATION/GATING
In the broadest definition, sound stimulation can be defined as the excitement of the nervous system by auditory information. Sound stimulation auditory retraining narrows the focus. In this context, a precise application of electronically processed sound, through headphones, can have the effect of retraining the auditory mechanism to take in a wider spectrum of sound frequencies. An ear that cannot process tone properly is a problem of great magnitude. Sufficient auditory tonal processing is a prerequisite to normal auditory sequential processing.
Auditory tonal processing (ATP) may be defined as the ability to differentiate between the tones utilized in language.
Auditory sequential processing (ASP) is the ability to link pieces of auditory information together.
Auditory tonal processing is a basis for more complex levels of auditory sequential processing. ASP is the ability to receive, hold, process, and utilize auditory information using our short-term memory. As the foundation for short-term memory, ASP is one of the building blocks of thinking.
Sequential processing functions are fundamental to speech, language, learning, and other perceptual skills. The ability to interpret sound efficiently provides the neurological foundation for these sequential functions. Per neurodevelopmental specialist Robert J. Doman Jr., "many people who have experienced auditory processing deficits have seen their sequential functions return and/or improve when proper tonal processing is restored."
The primary sound application used in the remediation of impaired tonal processing was created by Alfred Tomatis. Further discussions cannot take place without absolute acknowledgment of his pioneering research. The current field of sound stimulation auditory retraining evolves from Tomatis's discoveries of the powerful effect of filtration and gating of sound.
In the context of auditory retraining, let's summarize these terms:
Filtration means the removal of specific frequencies from an existing sound recording, be that the music of Mozart or a recording of a voice. Through the use of sound processing equipment, it is possible to isolate and mute certain frequency bandwidths. With filtration, any part of the low, mid, or high end of a recording can be withdrawn and reintroduced at will. On a visual level, imagine erasing the bottom part of a picture and then eventually drawing it back in. This is filtration.
Gating refers to the creation of a random sonic event. This is accomplished by electronically processing a soundtrack so it unexpectedly jumps between the high and low frequencies. While not always pretty to listen to, the net effect of this sound treatment is an extensive exercising of the muscles of the middle ear. The combined process of filtration and gating creates a powerful auditory workout. And for good reason! The middle ear mechanism must work very hard to translate the complexity of the “treated” incoming sound.
In Sound Remedies, the primary program featuring filtration/gating is The Listening Program .
"Filtration/Gating" is excerpted from The Power of Sound, published by Healing Arts Press.
(c) 2001 Joshua Leeds. All rights reserved.