RICHARDSON, Texas (Dec. 9, 2002) – Deaf children have the best chance of acquiring hearing, speech and language skills if they receive a cochlear implant by three and one-half years of age, a study by researchers in Texas and Arizona shows. Therapeutic intervention beyond that age is less likely to be efficacious, the study suggests.
The findings could influence an ongoing debate between clinicians who provide cochlear implants and “deaf culture” advocates who contend that parents of hearing-impaired children should forego implants and instead wait until those children are 18 years of age so that they may decide their course of treatment for themselves. The study suggests that 18 years is too long a period to wait – that by that age, the auditory nervous system has lost the ability to respond normally to sound, which is necessary for the normal development of speech and language skills.
The study was published in the December issue of the journal Ear and Hearing. It is co-authored by Dr. Anu Sharma, associate professor at the Callier Center for Communication Disorders at The University of Texas at Dallas (UTD), and Dr. Michael Dorman and Anthony Spahr, both of Arizona State University.
The researchers examined the electrical activity of the brain in response to sound in children and teenagers who received a cochlear implant – a device that is surgically inserted into the inner ear to electrically stimulate the auditory pathways, thus providing sound to deaf individuals.
The researchers found that the auditory system can survive up to three and one-half years of sound deprivation and still remain responsive – that is, can change quickly once sound is introduced through a cochlear implant. In contrast, if children were deprived of sound for seven or more years, the brain’s ability to respond to sound was greatly diminished.
“These results provide some of the strongest support to date for the concept of a ‘sensitive period’ for auditory development in children,” said UTD’s Sharma. “Overall, the results suggest that the best time to implant a deaf child is within the sensitive period, that is, by three and one-half years of age.”
The study is consistent with other speech and language studies showing improved outcomes for cochlear implantation when done relatively early in life.
About the Callier Center for Communication Disorders
Established in the early 1960’s, the Callier Center is renowned for advances in the treatment and prevention of communication disorders. The center is located on Inwood Road in Dallas, adjacent to major medical facilities such as The University of Texas Southwestern Medical Center at Dallas, St. Paul Hospital and Parkland Hospital. Part of UTD’s School of Human Development, the center educates future clinicians and researchers, offers state-of-the-art clinical and educational services and conducts innovative research.
About UTD
The University of Texas at Dallas, located at the convergence of Richardson, Plano and Dallas in the heart of the complex of major multinational technology corporations known as the Telecom Corridor, enrolls more than 13,000 students. The school’s freshman class traditionally stands at the forefront of Texas state universities in terms of average SAT scores. The university offers a broad assortment of bachelor’s, master’s and doctoral degree programs. For additional information about UTD, please visit the university’s web site at http://www.utdallas.edu.