Psychoacoustic Techniques

The following notes explain our music processing techniques, all of which are safe and have been tested over many years of application to both children and adults.

Bone conduction: Most of us are not aware of it, but we hear sounds in 2 ways – through air conduction and bone conduction. The odd sensation of hearing our own voice on a recording and not recognizing it is because on the recording we only hear the air conducted sound of our voice. When we speak, we hear our voice through both air and bone conduction (which is why when we go to an audiologist to have our hearing checked, a vibrator is placed on the mastoid bone right behind the ear to test our bone conduction response).

Lower frequencies in particular lend themselves to conduction by bone. These frequencies seem to have a very positive effect on our vestibular function. The process is as natural and safe as listening to a church choir or talented baritone voice, yet yields significant results with Integrated Listening Systems (iLs) protocols.

Frequency Filtration: Based partly on the theory that those who can hear more of the auditory spectrum have an advantage in learning, Integrated Listening Systems (iLs) programs employ gradually increasing filtration levels. By filtering, or letting only certain frequencies through, we are able to selectively train parts of a client’s auditory spectrum, improving learning-related abilities such as pitch discrimination (selectivity), sound decoding, and auditory memory.

Gating: The muscles of the inner ear have as one of their functions the job of screening out unwanted sounds. Integrated Listening Systems (iLs) gating separates music into 2 channels, alternating (or “gating”) them, with one channel boosting high frequencies and the other channel boosting low frequencies as the music volume increases and decreases. This causes the muscles in the middle ear to continuously tighten and relax, a process that strengthens them. As the muscles become stronger so does our ability for focused listening and paying attention.

Interactive Language Program: Audio/Vocal training is incorporated into the latter part of Integrated Listening Systems (iLs) programs once the auditory foundation is in place to train our speaking voices. The training involves reading aloud and repeating phrases into a microphone, and then listening to the play-back. This develops the auditory/vocal feedback loop: Is what I am saying matching what I intended to say? Am I speaking clearly? A rich speaking voice has the natural effect of continually energizing and stimulating the brain. The audio/vocal training is also used as a means of helping those who are left-ear dominant strengthen their right ear listening capability.

More on the listening treatment:

The listening treatment is also aimed at the sensory level involving an individual’s self-regulation and adaptation to the external world. There are many studies indicating that sensory deficiency or overload can result in delayed or uncommon development. It is believed that the central nervous systems of individuals with  following disorders including Attention Deficit (Hyperactivity) Disorders (ADHD), Auditory Processing Disorders, Autism, Developmental Disorders, Dyslexia, Dyspraxia, Learning Disabilities, Pervasive Developmental Disorder (PDD), Sensory Integration Disorders and  Speech and Language Disorders who do not properly recognize, process and organize sensory information from their bodies or environment. As a result, they are not able to respond or perform optimally.

Without re-training of the auditory system, this cycle continues with increasingly more disorganized sensory input, output and feedback. The consequences of a disorganized central nervous system are developmental lags, behavioral, emotional and learning issues. Without an efficient nervous system, it is very difficult to interact or be at ease with the world around us.

ILS listening by itself is not an FDA approved stand-alone program (as is the case with all sound interventions) and is not recognized in the USA as a medical intervention that seeks medical reimbursement. At our center we focus on occupational and physical therapy services in an adult-child one to one ratio and we add ILS listening as one of our many tools.