Purpose: Open-plan classroom styles are increasingly being adopted in Australia despite evidence that their high intrusive noise levels adversely affect learning. The aim of this study was to develop a new Australian speech perception task (the Mealings, Demuth, Dillon, and Buchholz Classroom Speech Perception Test) and use it in an open-plan classroom to assess how intrusive noise affects speech perception. Method: The first part of this article describes how the online 4-picture choice speech perception task materials were created. The second part focuses on the study involving twenty-two 5- to 6-year-old children in an openplan classroom who completed the task while other classes engaged in quiet and noisy activities. Results: Children's performance accuracy, number of responses, and speed were lower in the noisy condition compared with the quiet condition. In addition, children's speech perception scores decreased the farther away they were seated from the loudspeaker. Overall, the children understood and were engaged in the task, demonstrating that it is an appropriate tool for assessing speech perception live in the classroom with 5- to 6- year-old children. Conclusions: The results suggest that the Mealings, Demuth, Dillon, and Buchholz Classroom Speech Perception Test is a helpful tool for assessing speech perception in classrooms and that it would be beneficial to use in future research investigating how classroom design and noise affect speech perception.