This study explores audio theory and how product structure and material choice influence the generation of (unwanted) sound effects. The Philips Advent breast pump served as a case study to apply these insights, aiming to reduce negative acoustic experiences during use. The existing design was first measured and analysed with dedicated instruments to qualify the sounds. Combined with user feedback, this analysis informed subtle redesigns targeted to address specific issues—such as removing sharp high-pitched or low humming noises—after which they were evaluated.