The human brain is complex and fascinating, and while much has been learned, there is still more to discover about this powerful organ that conducts the orchestra of human body function. What we do know is that the brain is remarkably flexible and adaptable. As the fetal brain develops, its surface expands through folds and grooves, a process called gyrification1. This allows more cells and connections to support learning, memory, speech and other complex functions. From early development through adulthood, the brain responds to experiences and information by creating new connections, strengthening existing ones, and reorganizing neural pathways to compensate for atypical occurrences. The brain’s capacity for learning, adapting and evolving is called neuroplasticity, and it’s especially striking in babies.
The Hidden Work of Hearing
While the ears collect sound information, hearing takes place in the brain2. The process begins when soundwaves enter the outer ear, travel through the ear canal and vibrate the eardrum. Tiny bones in the middle ear transmit sound to the cochlea, the organ of hearing. The cochlea is a spiral-shaped, fluid-filled structure in the inner ear. Hair cells, specialized sensory cells in the cochlea detect sounds ranging in volume and pitch causing chemical exchanges that produce electrical signals. Those signals travel along the auditory nerve to the brain, where they’re processed in stages; first in the brainstem for initial sound analysis and then in the thalamus for more complex processing. Finally, the signals reach the auditory cortex, the brain’s hearing “headquarters”. There, they’re translated into meaningful sounds based on the listener’s experience, such as a knock on the door, the cry of a cat, or the voice of a loved one3. The ears capture sensory information, and the brain makes sense of it, determining its meaning and relevance.
Hearing Science, Screening and Technology
The first three years of a child’s life represent a critical window for brain development. By age five, approximately 90% of brain development is complete. Shortly after birth, newborns undergo a hearing screening. Its purpose is to detect potential hearing loss early in development so that further evaluation and diagnosis can occur without delay.4 Undetected hearing loss can have significant impact on a child’s ability to interpret sounds and speech patterns, acquire language, and develop cognitively, socially and emotionally. Synchronous development across these areas is essential for a successful transition to school.
Use of hearing assistive technology (HAT) greatly improves outcomes in children diagnosed with hearing loss. Devices such as hearing aids and cochlear implants work in different ways, but both can provide access to the sounds of speech, enabling children who are deaf or hard of hearing to develop listening and language skills in a timely manner. Hearing aids amplify sound and direct it to the inner ear for processing. Cochlear implants are surgically placed in the cochlea, where they bypass damaged hair cells and deliver electrical signals directly to the auditory nerve for interpretation by the brain. These devices do not eliminate deafness but provide children with enough access to speech sounds to help them develop spoken language. Being able to hear how words sound makes learning to speak easier and more natural.
Optimizing Outcomes with Early Support
Birth to age three is a key period for detection and intervention, marked by rapid brain growth and heightened neuroplasticity. With early use of hearing assistive technology and timely intervention, ideally by six months of age, children with hearing loss can build strong neural pathways for listening and spoken language, leading to significantly better outcomes. By acting early and taking advantage of the brain’s inherent flexibility, families can give their children tools to develop the listening, spoken language, and learning skills necessary to connect, contribute and live life with confidence and choice.
More Resources
Learn more about neuroplasticity through a first-hand lens in The Neuroplasticity of the Brain After a Cochlear Implant by Vibha, a proud Clarke alum and Temple University student. Read about Vibha’s own inspiring journey here.
Find more Clarke resources on brain development and early intervention here:
Check out our Teleservices Program for more information and to book a free consultation. Find more Clarke resources on Teleservices here:
CSU Donor Spotlight: The Brook J. Lenfest Foundation
Since 2009, Clarke Schools for Hearing and Speech has benefited from the support of the Brook J. Lenfest Foundation.
Founded by Brook J. Lenfest in 2000, the Philadelphia-based foundation champions opportunities through education, job training and mentoring. Its contributions continue to help Clarke Pennsylvania provide children who are deaf or hard of hearing with the listening and spoken language skills they need to succeed.
We are grateful for the Foundation’s ongoing commitment to empowering children and families and thank them for their support.
References –Why Timing Matters: Neuroplasticity, Cochlear Implants, and Early Support
1 Mihailov, A., Pron, A., Lefèvre, J., Deruelle, C., Desnous, B., Bretelle, F., Manchon, A., Milh, M., Rousseau, F., Girard, N., & Auzias, G. (2025). Burst of gyrification in the human brain after birth. Communications biology, 8(1), 805. https://doi.org/10.1038/s42003-025-08155-z
2 Augusta University. (2018, December 13). How Sound Reaches the Brain: The Biology of Hearing. Neuroscience of Hearing — Grades 6–12. Medical College of Georgia at Augusta University. https://www.augusta.edu/mcg/discovery/bbdi/neuroscience-of-hearing/6-12.php (augusta.edu)
3 National Institute on Deafness and Other Communication Disorders. (2022, March 16). How Do We Hear? U.S. Department of Health and Human Services, National Institutes of Health. https://www.nidcd.nih.gov/health/how-do-we-hear
4 National Institute on Deafness and Other Communication Disorders. (2024, June 10). Your Baby’s Hearing Screening and Next Steps. U.S. Department of Health and Human Services, National Institutes of Health. https://www.nidcd.nih.gov/health/your-babys-hearing-screening-and-next-steps
5 Tomblin, J. B., Oleson, J. J., Ambrose, S. E., Walker, E., & Moeller, M. P. (2014). The influence of hearing aids on the speech and language development of children with hearing loss. JAMA otolaryngology– head & neck surgery, 140(5), 403–409. https://doi.org/10.1001/jamaoto.2014.267
6 Meinzen-Derr, J., Wiley, S., & Choo, D. I. (2011). Impact of early intervention on expressive and receptive language development among young children with permanent hearing loss. American annals of the deaf, 155(5), 580–591. https://doi.org/10.1353/aad.2011.0010
References – Did You Know Fact 1
7Rabinowitch, I., & Bai, J. (2016). The foundations of cross-modal plasticity. Communicative & integrative biology, 9(2), e1158378. https://doi.org/10.1080/19420889.2016.1158378
