This paper presents an experimental design of a dual-task experiment aimed at exploring the salience of auditory notifications. The first task is a Sustained Attention to Response Task (SART) and the second task involves listening to a complex store soundscape that includes ambient sounds, background music and auditory notifications. In this task, subjects are asked to press a button when an auditory notification is detected. The proposed method is based on a triangulation approach in which quantitative variables are combined with perceptual ratings and free-text question replies to obtain a holistic picture of how the sound environment is perceived. Results from this study can be used to inform the design of systems presenting music and peripheral auditory notifications in a retail environment.