The ability to recognise words from the aural modality is a critical aspect of successful second language (L2) listening comprehension. However, little research has been reported on computer-mediated development of L2 word recognition from speech in L2 learning contexts. This report describes the development of an innovative computer application to improve L2 word recognition from speech, and goes on to describe an exploratory study of its use by 33 English as a second language (ESL) students. The study detected significant differences between word recognition scores measured before and after participants used the application. The manner with which students engaged with the computer application in terms of word recognition, self-determined exposure to speech input (repetitions) and modified output productivity (revisions) are also described and analysed. Differences in engagement by learners with different word recognition capabilities are noted. The paper concludes with a discussion of some recommendations for the use of computer-assisted development of L2 word recognition from speech and also provides concrete suggestions for much needed further empirical research in this area.