Route choice is a fundamental requirement in the evacuation process. The aim of this paper is to identify a method to simulate crowds in large indoor spaces with consideration of the acoustic system. This paper first extends an existing cellular automaton model and proposes a cellular automaton crowd route choice model (CACR model) to simulate evacuees in large indoor spaces. It then defines a measure for evaluating the utility of evacuation time using the CACR model under different circumstances, such as a fire situation or different voice warning systems, which other commercial models cannot simulate. The analysis of the characteristics of a sound field in large indoor spaces is based on field measurements. An observation experiment in a gymnasium is employed to test the proposed model in a stadium evacuation scenario. The results demonstrate that the CACR model can accurately simulate the evacuation process in large indoor spaces under various circumstances.