PhD in Surgery
Date of registration
Professor Michael Chi Fai TONG
Professor Patrick Chun Man WONG
Professor Kathy Yuet Sheung LEE
Field of research/intended thesis title
Testing hearing in noise using functional near-infrared spectroscopy (fNIRS): From neural correlates to intervention
Introduction of research study
Despite great successes booked in the research and development of the multichannel cochlear implant (CI) ever since its inception in the late 1970's, CI users still experience huge challenges in speech comprehension up until today. With the CI already relaying an already degraded signal, it's especially challenging to comprehend speech in noisy environments. Yet as we all experience in everyday life, we inescapably walk from one noisy setting into another: wind, traffic, music, babbling, you name it. So how could we potentially improve speech in noise comprehension? A major step in improving these postimplantation outcomes starts with the ability to accurately and specifically test these outcomes. This rings especially true for CI users where current clinical testing material are or are by and large unsuitable, such as infant CI recipients. Actually, this group is arguably the most in need for alternative testing methodology due to the ever-decreasing age of CI implantation. Fortunately, inspiration for such alternative methodology is quickly found. Recent developments in neuroimaging and the application of machine learning to neuroimaging problems are increasingly enabling us to decode a patient's medical conditions from measured brain activation patterns.
With that in mind, the aim of my thesis research is to assess the feasibility of using the functional near-infrared spectroscopy (fNIRS) as clinical tool to augment current behaviour-based clinical testing materials of speech in noise comprehension.
Why fNIRS? The fNIRS is a comparatively inexpensive and noninvasive neuroimaging device with high tolerance for subject movement. Most importantly, fNIRS is compatible with wearers of the CI where electrophysiological methods and MRI are not. An added bonus is that the fNIRS generates only low volumes of auditory noise that might otherwise interfere with the auditory presentation of testing items. That said, it's not all as easy as pie though. A major challenge in using the fNIRS is its low spatial sensitivity compared to MRI. Stay tuned.