Controversy exists regarding the processes involved in creative thinking with the Remote Associates Test (RAT) and the Compound Remote Associates Test (CRAT). We report three experiments that aimed to shed light on the component processes underpinning CRAT performance by using the mere presence of task-irrelevant sound as a key theoretical tool. Experiments 1 and 2 revealed that CRAT performance was impaired relative to a quiet condition by the presence of sequences of changing letters and tones, respectively. In both experiments a non-changing sound (a repeated letter or a repeated tone) produced no disruption relative to quiet. Experiment 3 established that additional disruption was engendered by having to ignore meaningful speech as compared to meaningless speech. These experiments demonstrate that both semantic activation and subvocalisation are important determinants of successful creative thinking with CRAT problems. We suggest that semantic activation underpins solution-generation processes whereas subvocalisation underpins solution-evaluation processes.