AUDITORY BRAIN DEVELOPMENT: THE KEY TO DEVELOPING LISTENING, LANGUAGE AND LITERACY

This issue of of Hearing and Kids was written by my good friend Dr. Carol Flexer. She is a Distinguished Professor Emeritus of Audiology, The University of Akron. She is an international lecturer and author of more than 155 publications, and is a past president of the Educational Audiology Association, the American Academy of Audiology, and the AG Bell Academy for Listening and Spoken Language. She has co-edited two books with me and we frequently present together.

 

Through newborn hearing screening, infants are receiving amplification in the first months of life. Consequently, we can stimulate the auditory cortex in ways that were not possible a few years ago with older technologies. Auditory language embellishment and enrichment now can be provided during critical periods of maximum brain neural plasticity — the first few years of life. As a result, today’s babies and young children who are born deaf have incredible possibilities for achieving higher levels of spoken language, reading skills, and academic competencies than were available to most children in previous generations.

 

Auditory Neural Development

The purpose of a cochlear implant or a hearing aid is to access, stimulate and grow auditory neural connections throughout the brain to provide the foundation for spoken language, reading and academics. Due to neural plasticity, age at amplification/implantation is critical–younger is better, and early and ongoing auditory therapy is absolutely essential, regardless of the amplification device used.

Robbins et al. (2004) found that skills mastered as a course of normal development result in developmental synchrony. Therefore, it appears we are pre-programmed to develop specific skills during certain periods of development. If those skills can be triggered at the intended time, we will be operating under a developmental and not a remedial paradigm. That is, we will be working harmoniously within the design of the human structure.

Furthermore, mastery of any developmental skill depends on cumulative practice; each practice opportunity builds on the last one. The brain demands a great deal of practice before specific neural organization patterns will be developed. Therefore, the more delayed the age of acquisition of a skill, the farther behind children are in the amount of cumulative practice they have had to perfect that skill. The same concept holds true for cumulative auditory practice. Reduced auditory practice leads to delayed auditory neural development, and that leads to delayed language skills, all of which will necessitate using a remedial rather than a developmental instructional paradigm.

 

Literacy Development

Listening experience in infancy lays the foundation for the development of spoken language and literacy.

Literacy plays an important role in personal fulfillment and participation in society because it acts as a type of currency in exchange for improving one’s quality of life.

Laying the foundation for emergent literacy skills should begin as soon as the child is amplified/implanted. Exposure to print can be initiated similarly to that of the child with normal hearing. Board books that are interactive and encourage the child to touch pages and listen to sounds offered by the text can be introduced to infants and toddlers.

Personalizing early exposure to print by creating an experience book or photo album can ignite interest in even the most reluctant early reader. A child’s attention span cannot be expected to be lengthy at the outset, but it can be gradually extended. Furthermore, exposing the child to various literary formats that are purposeful, such as narratives, informational books, poetry, folklore, recipes, persuasive texts, letters, invitations, and thank you notes, offers  the child examples of print that she encounters daily. These functional opportunities to interact with print make reading fun, purposeful and relevant.

The art of reading aloud to the child to condition the brain to associate reading with pleasure becomes an early priority in family training. Interaction with print is one of the primary ways to expand a child’s vocabulary, auditory memory, attention span, and familiarity with the syntax of spoken language.

Writing grows from reading. Writing can be reinforced as a medium for conveying meaning by having the preschooler “write” notes to the family. The notes can be tacked to the wall and referred to as reminders as the child displays emergent writing skills.
Functional Listening Checks and Knowledge of a Child’s Distance Hearing – a First Step


Because working with children who have hearing loss is all about “the brain,” we must ensure that equipment is checked daily by performing a functional listening check. Sound must actually reach the brain for auditory learning to occur.

Parents and therapists should be armed with a stethoscope, a battery checker, an earwax pick and a blower for children wearing hearing aids. Professionals need to ensure that parents and other service providers have adequate training and comfort with their children’s equipment.

For cochlear implants, each manufacturer publishes a troubleshooting guide specific to the make and model of each device. Some cochlear implants have a microphone tester, some have a signal checker, and some have lights and or beeps that provide different information.

If a child is not hearing all of the sounds of speech at soft levels and at distances (and a child’s distance hearing should be known), either with hearing aids or an implant, then the next questions should be, “Why not” and “How can we fix it”? The child’s technology must allow her to overhear conversations of others; the brain must have acoustic access to incidental as well as intentional spoken language.

Summary
To summarize, neuroplasticity is greatest during the first 3 ½ years of life; the younger the infant, the greater the neuroplasticity. Rapid infant brain growth requires prompt intervention, typically including amplification and a program to promote auditory skill development. In the absence of sound, the brain re-organizes itself to receive input from other senses, primarily vision; this process is called “crossmodal re-organization” and it reduces auditory neural capacity. Early amplification or implantation stimulates a brain that has not yet been reorganized, allowing the brain to be more receptive to auditory input resulting in greater auditory capacity.

Furthermore, early amplification/implantation synchronizes activity in the cortical layers. Therefore, identification of newborn hearing loss should be considered a neurodevelopmental emergency.

Resources

1. Cole E., & Flexer, C. (2011). Children with hearing loss: Developing listening and talking, birth to six, 2nd ed. San Diego, CA: Plural Publishing.

2. Madell, J., & Flexer, C. (2008). Pediatric Audiology: Diagnosis, Technology, and Management. New York: Thieme Medical Publishers.

3. Madell, J., & Flexer, C. (2011). Pediatric Audiology Casebook. New York: Thieme Medical Publishers.

4. Nicholas, J. G., & Geers, A. E. (2006). Effects of early auditory experience on the spoken language of deaf children at 3 years of age. Ear & Hearing, 27, 286–298.

5. Robbins, A.M., Koch, D.B., Osberger, M.J., Zimmerman-Philips, S., & Kishon-Rabin, L. (2004). Effect of age at cochlear implantation on auditory skill development in infants and toddlers. Archives of Otolaryngology – Head & Neck Surgery, 130(5), 570-574.

6. Robertson, L. (2009). Literacy and Deafness: Listening and Spoken Language. San Diego: Plural Publishing

7. Sharma, A., Tobey, E., Dorman, M., Bharadwaj, S., Martin, K., Gilley, P., & Kunkel, F. (2004). Central auditory maturation and babbling development in infants with cochlear implants. Archives of Otolaryngology – Head & Neck Surgery, 130(5), 511-516.

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About Jane Madell

Jane Madell has a consulting practice in pediatric audiology. She is an audiologist, speech-language pathologist, and LSLS auditory verbal therapist, with a BA from Emerson College and an MA and PhD from the University of Wisconsin. Her 45+ years experience ranges from Deaf Nursery programs to positions at the League for the Hard of Hearing (Director), Long Island College Hospital, Downstate Medical Center, Beth Israel Medical Center/New York Eye and Ear Infirmary as director of the Hearing and Learning Center and Cochlear Implant Center. Jane has taught at the University of Tennessee, Columbia University, Downstate Medical School, and Albert Einstein Medical School, published 5 books, and written numerous books chapters and journal articles, and is a well known international lecturer.