Being able to pronounce a language so that a listener can understand (i.e., intelligibly) is critical to achieving communicative competence (Munro & Derwing, 1995), but is Duolingo helpful in this regard? Given Duolingo's status as the world's most widely used language-learning app (Hirschi, 2020), understanding its potential is important to English teachers in Australia, who might wonder whether to incorporate Duolingo into their pronunciation teaching strategy. The present study examines whether Duolingo's implicit pronunciation teaching is as effective as that of a human teacher in a classroom -- a question which has not been well researched to date. In the design of this study, the researchers sought to avoid some of the methodological problems from Jiang et al. (2021). First of all, the participants in the current study shared the same first language (Mandarin); second, Duolingo users' results were compared to a control group, rather than self-set targets; third, all participants were included in the evaluation; and fourth, the study experienced a high completion rate. This greatly reduced the impact of attrition, self-selection, or unsuccessful completion of the test on the data. This report seeks to answer the following research question: To what extent is Duolingo effective at promoting implicit pronunciation learning, especially as compared to human teachers?