Hearing Research Supported by the Masonic Foundation of Ontario
In 1978, to celebrate the 125th Anniversary of Grand Lodge in 1980, the Foundation initiated a fund-raising campaign expressly to support medical research into hearing problems of the inner ear, particularly to contribute to development of the Cochlear Implant Program. "Project H.E.L.P." (Hearing for Every Living Person) raised a capital fund of $600,000. With the interest earned, the Masonic Foundation supports the Auditory Science Laboratory at The Hospital for Sick Children. Contributions have totaled approximately $1.3 million since the inception of the project.
The funding has supported research in the areas of both basic and clinical research. In particular Dr. Harrison has been examining the development of the brain involved in perceiving sound. The auditory system is already wired up in a rather simple fashion. When the system is activated by environmental sounds (speech sounds as an example) central regions of the system become specialized for detecting the signals that the subject has been exposed to. Dr. Harrison's group has discovered in a neonatal subject, at the level of cerebral cortex, auditory neurons start out being responsive only to very simple sounds, but over time with exposure to the sound environment, these neurons form networks and become responsive to complex sounds (such as speech).
In the clinical area, Dr. Harrison's group continues research into otoacoustic emissions (recording of small signals that come out of the ears when they have normal function). With new techniques, they have been experimenting to see if they can monitor some aspects of central auditory function (as opposed to just inner ear activity). Another clinical study is to measure evoked potentials (brain-waves) from children with cochlear implants. This is part of a longitudinal study in which they will test infants just after implantation and then retest at yearly intervals to track developmental changes. These studies have been recently published. The next question relates to bilateral cochlear implantation and whether two implants are better than one. In addition, they are testing whether a second implant in the ear opposite to one implanted a number of years before, will be of benefit.
The two year Millennium project of the Masonic Foundation of Ontario, in conjunction with the Grand Lodge, was to develop within Ontario, a system which will allow the early detection of hearing loss in neonates and infants, and then to guide them to an appropriate treatment strategy. The goal was to provide hearing impaired children the earliest opportunity to develop their communication abilities, have normal educational and career prospects, and most importantly, improve their quality of life. Shortly after this project was initiated, the Government of Ontario instituted the Ontario Infant Hearing program. However, the Millenium project continued and raised over $2.1 million which is now being used to advance research to help hearing-impaired infants.
Three research projects are currently being funded through this program.
Dr. Robert Harrison at The Auditory Science Laboratory, The Hospital for Sick Children in Toronto, has been studying the genetic causes of hearing loss. Dr. Harrison's group has been trying to determine the underlying genetic causes for the severe to profound deafness in the children in the cochlear implant program. They are studying a particular type of hearing loss called GJB2-related deafness. By comparing the cochlea in GJB2-related hearing loss with those from non-GJB2 related hearing loss they were able to show a difference between these two cases. These findings suggest that, in the future, it might be possible to customize the implantable devices for patients with hearing loss based on genetic testing.
Drs. Richard Seewald and Susan Scollie at the Child Amplification Laboratory, National Centre for Audiology, University of Western Ontario, are working on projects aimed to develop procedures for predicting aided speech sound perception in children who use hearing aids and to develop computerized displays of test results easily understood by hearing care professionals and caregivers. The hope is that these two lines of investigation will help clinicians and families better understand whether a child is receiving appropriate levels of benefits from their hearing aids.
Dr. Andre Durieux-Smith and colleagues at the University of Ottawa/CHEO Research Institute Audiology Research Laboratory are investigating factors that can influence the development of children with a permanent hearing loss. Such factors include the age of diagnosis of hearing loss, hearing technology such as cochlear implants and the type of intervention program in which the child with hearing loss and his/her family are enrolled. The study supported by the funding The impact of screening and case finding on the functional status of children with a hearing impairment has been enrolling participants for a number of years. As a longitudinal study (one which looks at the same participants over a number of years), it has provided data on children enrolled in AV (auditory-verbal) programs compared to their hearing peers. Although there are differences between the two groups of children in the areas of speech and language, there was not a consistent difference in other areas. A subset of children enrolled in this study have cochlear implants which has provided an excellent opportunity to obtain data on their development in comparison to the other participants.
Although very different in their approaches, these three studies continue to yield valuable information regarding the complexities of hearing loss.