Audiology Keynote Sessions Probe Hair Cell Research, Other Hot Topics More than 750 ASHA-certified audiologists gathered in Philadelphia to learn about the latest developments in hair cell regeneration, current trends in amplification, and diagnosis and follow-up of early hearing loss in infants-the topics of daily keynote addresses, each of which featured a panel of three distinguished speakers. In addition, participants ... ASHA Convention Coverage
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ASHA Convention Coverage  |   December 01, 2004
Audiology Keynote Sessions Probe Hair Cell Research, Other Hot Topics
Author Notes
  • Linda Vaughan, is ASHA’s Director of Audiology Adult Practice. Contact her through the Action Center at 800-498-2071, ext. 4191 or by e-mail at tmullins@asha.org.
    Linda Vaughan, is ASHA’s Director of Audiology Adult Practice. Contact her through the Action Center at 800-498-2071, ext. 4191 or by e-mail at tmullins@asha.org.×
  • Tina Mullins, is ASHA’s Director of Audiology Practice Management. Contact her through the Action Center at 800-498-2071, ext. 4112 or by e-mail at lvaughan@asha.org.
    Tina Mullins, is ASHA’s Director of Audiology Practice Management. Contact her through the Action Center at 800-498-2071, ext. 4112 or by e-mail at lvaughan@asha.org.×
Article Information
Hearing & Speech Perception / Hearing Disorders / ASHA Convention Coverage
ASHA Convention Coverage   |   December 01, 2004
Audiology Keynote Sessions Probe Hair Cell Research, Other Hot Topics
The ASHA Leader, December 2004, Vol. 9, 1-13. doi:10.1044/leader.ACC2.09222004.1
The ASHA Leader, December 2004, Vol. 9, 1-13. doi:10.1044/leader.ACC2.09222004.1
More than 750 ASHA-certified audiologists gathered in Philadelphia to learn about the latest developments in hair cell regeneration, current trends in amplification, and diagnosis and follow-up of early hearing loss in infants-the topics of daily keynote addresses, each of which featured a panel of three distinguished speakers. In addition, participants attended other sessions on a wide range of clinical and professional topics as part of the Audiology Convention at ASHA on Nov. 18-20.
“The Audiology Convention was a big success. It lived up to our theme of ‘United in Science and Service,’” said audiologist Dennis Burrows, 2004 ASHA Convention Co-Chair. “Everyone enjoyed the convention site and the educational offerings, which ranged from the very practical to the theoretical.”
“ASHA offers something unique for audiologists at this annual convention-the opportunity to collaborate with colleagues outside of audiology, and to address topics that affect the entire discipline of communication sciences and disorders, both from the research and practice perspectives.”
In particular, Burrows noted the excellence of the keynote addresses. “The speakers were the best in the profession and addressed very timely topics. The potential of hair cell regeneration-the topic of the first keynote-is very exciting,” he said, adding that other sessions “provided information that I can immediately apply in my practice-ototoxic monitoring, the auditory steady state response and hearing aid assessment are just a few examples.” Topics included auditory processing disorder and cochlear implants.
Below is a summary of the first of the three keynote addresses, in which a total of three speakers offered their perspectives and/or research findings. The other two keynote addresses will appear in the Jan. 18 The ASHA Leader.
Rescue, Repair and Regeneration in the Inner Ear
Thursday’s panel of keynote speakers addressed the topic, “Rescue, Repair and Regeneration in the Inner Ear.”
The first presenter was Sharon Kujawa, PhD, associate professor and director of the Department of Audiology for the Massachusetts Eye and Ear Infirmary, Boston, who spoke on “Minimizing Acquired Sensorineural Hearing Loss.” She addressed the genetic contributions to acquired hearing loss susceptibility, and discussed her laboratory’s efforts to use this research to develop inner ear therapies.
Kujawa pointed out that current treatments for hearing loss, including hearing aids, cochlear implants and assistive listening devices, are useful tools but they “cannot increase a damaged ear’s basic capacity.”
She asked, “What if we discover what makes some more susceptible to hearing loss, and what if we could develop treatments for protection and repair?”
Her laboratory focuses on four study areas: vulnerability to acquired sensorineural hearing loss; drugs as tools; drugs as therapy; and hair cell regeneration.
Most audiologists are aware of variability in the vulnerability to hearing loss. But is this resistance to noise-induced hearing loss inherited? Based on various studies of inbred animals, buffers to the physical effects of toxic noise are genetically determined. The ultimate identification of genes influencing NIHL susceptibility will eventually form the basis for development of pharmacologic interventions to prevent or minimize noise-induced ototrauma.
Another avenue being explored is pharmacologic intervention to prevent or minimize noise-induced ototrauma. Kujawa noted that the use of systemic drugs is problematic because of the side effects and the blood-cochlea barrier. Delivering drugs directly into the inner ear through the round window via the middle ear or direct infusion into the cochlea via micropumps are being explored.
Finally, Kujawa says she expects to see an increase in interdisciplinary research in order to add to the opportunities for clinical care.
Douglas Cotanche, PhD, director of research at the Department of Otolaryngology at Children’s Hospital, Boston, was the second speaker. He posed the question, “Can we develop a biological cochlear implant to treat sensorineural hearing loss?” Twenty years ago, researchers discovered that hair cells regenerated in birds, which fueled current research in exploring ways to repair and regenerate hair cells in humans. Cotanche is involved with research to explore the possibility of regenerating functional hair cells through stem cell implantation.
Therapeutic approaches to the mammalian ear include genetic manipulation to regenerate capacity, gene therapy to induce new hair cell production, and stem cell transplantation to induce replacement of lost or damaged cells. Cotanche added that research suggests that if hair cells are produced, nerves are also generated in the area around the hair cells.
Although evidence exists that transplanted cells differentiate to form the structure of damaged or lost cells, it is not yet clear if they replace function. One danger, however, of gene modification to induce new hair cell production is its potential to increase cancerous growths.
The question was raised regarding the controversy over stem cell research and if it had affected his work. Cotanche stated that current controversy is over the use of embryonic stem cells. It did not apply to his work for which non-embryonic stem cells are utilized.
Dianne Durham, PhD, the third speaker, explored the response of the central nervous system (CNS) to hair cell loss and regeneration. Durham, an associate professor in the Department of Otolaryngology at the University of Kansas Medical Center, outlined the impact on the CNS of removing the cochlea. She asked the question, “How is the central nervous system affected with the damage and subsequent repair of hair cells in the cochlea?” She noted that plasticity is important in the auditory system because it will affect whether repairs made to the cochlea can provide useful input to the CNS.
After removal of the cochlea in chickens, she noted that within hours, there was a cessation of 8th nerve activity, decreased glucose use and blood flow, ultrastructural changes, changes in metabolism, and an increase in intracellular calcium. Within days, removal of the cochlea causes death of 30% of the neurons, shrinkage of remaining neurons, and a decrease in metabolic activity.
Then she looked at the effects of hair cell regeneration on the CNS. Using gentamicin to destroy hair cells within the cochlea, she looked at physical regeneration and concomitant changes to the CNS. She noted that high-frequency otoacoustic emissions are not recovered as quickly as hair cells are restored. However, Durham stated that she and her colleagues were surprised to find that auditory neurons returned to normal as evidence of the brain’s plasticity in response to changes in the cochlea.
Otoprotection and Hair Cell Regeneration

Because of recent developments in auditory and vestibular hair cell regeneration, it is important to be aware of cellular changes in hair cells since sensorineural hearing loss will soon be treatable with drugs and molecular medicine therapies. To learn more about otoprotection, access the May/June 2004 Access Audiology on the ASHA Web site.

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December 2004
Volume 9, Issue 22