The effects of incidental learning and input frequency on the perception of non-native speech

The current study investigated the extent to which naive listeners could incidentally acquire non-native phonemic contrasts and the degree to which the frequency of exposure to the target phonemes affects their learning. A total of 100 English speakers were assigned to the following conditions: (1) 0-occurrence; (2) 2-occurrence; (3) 10-occurrence; (4) 20-occurrence; or (5) 30-occurrence. The participants watched a video that provided instruction on counting numbers in Korean while incidentally exposing them to various repetitions of the target phonemes. All participants completed a pretest, an immediate posttest, and a delayed posttest, each comprising an AX discrimination task. The effects of incidental exposure were found only in the 10-occurrence condition, in both the immediate posttest and the delayed posttest. While the current study demonstrates the overall efficacy of incidental exposure on the perception of non-native speech, it also highlights the important role that selective attention plays in language learning.