Using eye movements for analyzing the influence of linguistic complexity, noise, and hearing loss on sentence processing time

High linguistic complexity can reduce speech intelligibility and can increase cognitive effort. A method for detecting the latter was presented by Wendt et al. (2014) using an eye-tracking (ET) paradigm measuring increased processing time for complex sentences. This study evaluates this method and compares the ET method to electrooculography (EOG). The processing time of sentences with different linguistic complexity was measured in quiet and in modulated noise using ET and EOG simultaneously. Eleven participants with hearing impairment and five participants with normal hearing participated in the study. Processing times measured using ET and using EOG showed a correlation of 94%. Furthermore, our results confirm the findings of Wendt and colleagues, that more complex sentences show increased processing time. This study evaluated that sentence processing time can be analyzed equally well using ET and EOG. The method reveals characteristic consequences of linguistic complexity and noise on sentence processing time which can be used as an indicator of the cognitive effort during sentence comprehension