Several recent studies have examined an interaction between talker’s acoustic characteristics and spoken word recognition in speech perception and have shown that listener’s familiarity about a talker influences an easiness of spoken word processing. The present study examined the effect of listener’s familiarity about talkers on the free recall task of words spoken by two talkers. Subjects participated in three conditions of the task: the listener has (1) explicit knowledge, (2) implicit knowledge, and (3) no knowledge of the talker. In condition (1), subjects were familiar with talker’s voices and were initially informed whose voices they would hear. In condition (2), subjects were familiar with talker’s voices but were not informed whose voices they would hear. In condition (3), subjects were entirely unfamiliar with talker’s voices and were not informed whose voices they would hear. We analyzed the percentage of correct answers and compared these results across three conditions. We will discuss a possibility whether a listener’s knowledge about the individual talker’s acoustic characteristics stored in long term memory could reduce the quantity of the cognitive resources required in the verbal information processing.