A structured interview process is proffered as an effective means to advance prospective teachers' understandings of students as learners of mathematics, a key component of pedagogical content knowledge. The interview process is carried out in three phases with the primary objective of developing listening skills for accessing students' mathematical thinking. The interviews adhere to clinical interview procedures for discovering cognitive activities and, accordingly, are initiated by presenting an open-ended mathematics task. Three rounds of interviews were completed by undergraduates enrolled in a middle school mathematics methods course. Anecdotal data generated by their interview reports suggest that the structured interview process engenders an interpretive orientation to listening to students and furthers awareness of how students make sense of mathematics. Features of the interview process that may limit its potential benefits are discussed; recommendations for further study are proposed.