Current Studies

Bilateral auditory processing in children using bilateral cochlear implants

We are working to provide children with the hearing they need to grow and learn in such common and dynamic environments. With this in mind, we aim to promote spatial awareness to children with hearing loss by providing access to sound in both ears. Important information about the location of sound is missed in children who hear better from one ear than another. This complex process begins when the brainstem integrates information coming from our two ears and continues as the higher levels of the brain become involved.

The large cohort of children we are studying represent different conditions of auditory experience, according to whether they received one implant (unilateral implantation) or two implants (bilateral) and whether the bilateral implantation occurred simultaneously or sequentially, over a period of time. Also, some children can hear in one ear with or without a hearing aid and use a cochlear implant in the other.

Enhancing hearing with other senses
We are asking if children using cochlear implants can use visual information to supplement hearing important cues in speech and music. We have shown that children using cochlear implants find it more difficult to discern subtle cues in speech and music which convey emotion than do their peers with normal hearing.

Understanding the interaction between hearing and other senses will also give us insight into how the brain might have reorganized during the period of deafness and with cochlear implant use. This reorganization may go beyond the specific auditory pathways and be supported in the brain by different connections. With this in mind, we are examining both the primary and non-primary auditory pathways which contribute to hearing in children with normal hearing and in children using cochlear implants.

Vestibular and balance in children with hearing loss
We have found that many children with hearing loss also have balance problems. The inner ear sits in close proximity to the vestibular system and the sensory cells function similarly which likely explains the concurrent impairments.  Present studies concentrate on identifying which children with hearing loss also have vestibular/balance problems, providing clinically useful tools for screening balance problems in children, and improving balance function to improve spatial awareness and protect children from falls.

Long-term outcomes of cochlear implantation
We are interested in addressing important clinical issues related to children with hearing loss. A key area of focus for us has been to understand what factors contribute or detract from children’s ability to use a cochlear implant effectively in order to help support optimal outcomes after implantation. We have studied the effects of age and duration of deafness, communication mode, socioeconomic factors, and changes in device technology and are presently interested in effects of listening effort.

Surgical innovations
We have explored novel ways to perform cochlear implantation in children. Having developed a minimally invasive procedure, we are able to perform cochlear implantation in a shorter time, with very few complications. This has been important for providing cochlear implants to very young children less than 12 months of age and for safe implantation of two cochlear implants in the same operation. We have also worked to better understand the anatomy of the inner ear (cochlea) and auditory nerve as well as how new implant technologies affect behavioral and electrophysiological responses.

Clinical protocols
One of our primary objectives is to translate our research into clinical practice. Some examples of this translation include how we use electrophysiological responses to program unilateral and bilateral cochlear implants. This is extremely important because young children are unable tell us about what they are hearing through the cochlear implant.