This research aimed to investigate the effects of pronunciation monitoring on learners' affective factors through self-monitoring activities using speech recognition systems. The effect of a specifically designed pronunciation activity for Japanese university students was analyzed. The worksheet form of the activity was based on the use of speech recognition systems such as Siri and Google apps. A special focus was placed on the development of students' affective phase toward English and pronunciation learning. The research concluded that the activity had a positive impact for increasing awareness of, interest in, and motivation toward pronunciation improvement and it highlighted the important role of teaching pronunciation in English oral communication skills in the limited English exposure of the English as a Foreign Language (EFL) context. [For the complete volume, "CALL and Professionalisation: Short Papers from EUROCALL 2021 (29th, Online, August 26-27, 2021)," see ED616972.]