February 20, 1998

Fight against hearing loss gets boost

Fight against hearing loss gets boost

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Dr. David Haynes examines five-year-old cochlear implant patient Jonathan Byler. (Photo by Donna Jones Bailey)

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Five-year-old cochlear implant patient Jonathan Byler sports the external speech processor as he learns more about how the ear functions. (Photo by Donna Jones Bailey)

Vanderbilt University Medical Center¹s cochlear implant program, designed to improve the hearing of children and adults with severe hearing loss, will be expanded and improved thanks to the merging of the Bill Wilkerson Center and Vanderbilt University Medical Center.

The full-service implant program, the only one of its kind in Middle Tennessee, will offer implant patients a ³complete package,² said Dr. David S. Haynes, assistant professor of Otolaryngology and surgeon for the cochlear implant program.

When the newly created Vanderbilt Bill Wilkerson Center for Otolaryngology and Communication Sciences consolidates its many programs into a new facility on campus, the all-in-one location will be more convenient for cochlear implant patients at VUMC, Haynes said. The Wilkerson Center programs are currently scattered throughout the medical center.

³Bill Wilkerson allows us to be a complete package,² Haynes said, adding that the patients will undergo pre-surgical evaluation, surgery and post-surgical rehabilitation all at Vanderbilt.

A cochlear implant is suitable for both children and adults who are profoundly hearing impaired. Candidates are those who can¹t be helped by conventional hearing aids. The implant consists of an internal, quarter-sized, implanted device and an external speech processor worn on a belt, with newer implants having an ear-level speech processor.

Even children with congenital losses are not implanted until after two years of age. Adequate testing and observation are required to ensure that the hearing impairment can't be improved with conventional amplification.

³Whatever hearing impairment exists, research shows that the longer the hearing impairment has existed, the poorer the performance after the implant,² Haynes said. ³There is a lot of atrophy of the central auditory pathways that can occur when deafness exists. So if we¹re implanting a severely hearing-impaired person at the age of 35, in general they won¹t do as well as if we had implanted them at age three and they had grown up with sound awareness.²

VUMC is implanting two implants made by different companies. The two implants, with minor differences, have both been tested extensively and proven safe and effective to use for cochlear implants.

The small internal device has an electrode array that stimulates a small wire that is placed in the turns of the cochlea. The external device transmits the signal through the skin and attached by way of a magnet. The performance of the implants is improving because technology is improving, Haynes said.

³Now with the two companies competing against each other, advancements are accelerating more rapidly. The implant itself is relatively simple. It¹s the externally worn speech processor that benefits from the improved technology. They are becoming more powerful and smaller.²

The speech processor, on some implant models, is tiny enough to be worn at ear level, somewhat like a hearing aid, he said.

In addition to Haynes, others participating in the cochlear implant program are Dr. C. Gary Jackson, clinical professor of Otolaryngology; Anne Marie Tharpe, Ph.D., assistant professor of Hearing and Speech Sciences; Fred H. Bess, Ph.D., professor of Hearing and Speech Sciences and associate director of the center; James W. Hall III, Ph.D., associate professor of Hearing and Speech Sciences and Otolaryngology, Douglas D. Sladen, pediatric audiologist; and Mandy M. Lamb, audiologist.

One of the most important aspects of the implant program is a preoperative counseling and evaluation component, where it can be determined whether the patient will benefit from an implant.

³Probably no other operation done in this country has more preoperative counseling and evaluation than cochlear implantation,² Haynes said. ³Because we don't want to implant a device that¹s not going to be used, we want to make sure the patient is capable of wearing it. We need to make sure the patient has a desire to wear it and we want to make sure there is no misunderstanding about what the implant is and what it will do. In fact, if anything, we tend to lower patients' expectations of performance,² he said.

³The implant generally allows them to hear certain words better, to lip read better, and to utilize sound. Performance depends on various factors, with the most important being the length of time of deafness. The hearing has to be very poor to be a candidate,² he said.

The Vanderbilt Bill Wilkerson Center also takes responsibility after surgery to ensure that the child adapts and is educated in the proper environment that emphasizes speech and auditory skills. The emphasis applies to both school and home.

Recipients of the implant should also realize that the implant will not allow them to begin talking the very next day, Haynes said. Rehabilitation through the Vanderbilt Bill Wilkerson Center is essential and will take some time, he said.

The merger of the Bill Wilkerson Center into VUMC is the culmination of a close working relationship that has existed for years. The graduate training programs of the Vanderbilt Department of Hearing and Speech Sciences have always been physically located in the Wilkerson Center.

The new partnership is one of the nation¹s few communication disorders centers with expertise in clinical medicine, education and research.

The Vanderbilt Bill Wilkerson Center is in the midst of a $5 million capital campaign to support the new building and additional endowment for the Wilkerson Center programs and activities.