Unfamiliar accents can make speech communication difficult, both by reducing speech intelligibility and by increasing the effort listeners must put forth to understand speech. In general, intelligibility refers to the proportion of words that a listener can correctly identify (100%, 50%, etc.), while listening effort refers to the cognitive resources that must be devoted to a difficult listening task. Generally, lower intelligibility is related to higher effort. However, it is now apparent that these two constructs, while related, are independent: for example, two 100% intelligible speakers may elicit different amounts of effort. To better characterize the relationship between intelligibility and effort, this study presents speakers of four intelligibility levels (one L1 English speaker, and three Mandarin-accented English speakers) within a dual-task paradigm (featuring a vibrotactile secondary task) to measure listening effort. We hypothesize an inverse relationship between intelligibility and effort, but the shape and slope of this relationship are of primary interest. These results will begin to illuminate the relationship between intelligibility and effort across a more continuous range of accent intelligibility. Data collection is ongoing. Results for the Mandarin Chinese accent will be presented. Preliminary results for the study’s second iteration (using a Korean accent) will also be presented.