Over the last several years there has been increasing interest in developing objective methods for measuring the degree of cognitive resources that are required for understanding speech in noisy environments (sometimes called listening effort). Such methods could be used for reaching a deeper understanding of the interactions between cognitive and physiological mechanisms that support speech understanding, as well as for assessing the effectiveness of hearing devices or signal processing methods that attempt to reduce listening effort in complex listening environments.
Several candidate signals have been proposed to measure listening effort. Some (such as pupillometry) are measures of autonomic nervous system activity, while others measure brain activity thought to be reflect different arousal states (such as the alpha rhythm in the EEG). Functional near-infrared spectroscopy (fNIRS) is a relatively new method that can measure the change in haemoglobin oxygenation in the brain as groups of neurons activate. All these methods have the potential to measure listening effort as reflected by different aspects of brain and body states, however it is still not clear how or if these various measures will be correlated.
The aim of this project is to implement and test an experimental setup and paradigm where both pupillometry and fNIRS responses can be measured simultaneously during a speech-understanding task. The work of the project will involve helping to design and implement the experimental apparatus that will allow for the fNIRS and pupilometery data collection systems as well as the stimulus delivery system to be synchronised and operate simultaneously. You will also help design a simple test paradigm and test the system on several human volunteers.
This a group project ideally for two people. One student will focus on the technical implementation of the pupillometry and fNIRS systems and will need a background and strong interest in biomedical engineering, acoustical engineering, or another related area. You should be capable of working unsupervised with Matlab and Python and be happy tinkering with hardware. The second student will focus on developing and testing several candidate experimental paradigms that are suitable for testing speech understanding while simultaneously taking fNRIS and pupillometry measurements. For this part of the project it would be helpful to have some experience with speech tests in human participants, and a basic understanding of speech psychophysics or psychoacoustics. Both students will participate in finally testing the system in a small group of human volunteers.