The phenomenon of noise has resisted many attempts at framing it within a singular conceptual framework. Critically questioning the tendency to do so, this article asserts the complexities of different noise-phenomena by analysing a specific technology: technological noise reduction systems. Whereas Sterne describes how engineers have sought to eradicate noise in order to reach what Dolby Laboratories called an ‘exceptional purity of sound,’ Serres and Kittler repeatedly stress that the presence of noise is not only inevitable, but even fundamental to sound and sound recording. Working at the crossroads of noise as a concept in information theory and noise as a physical and sonic phenomenon, a close reading of technological noise reduction shows how it not only produces its own notion of noise in the very process of reducing it, but even generates noise itself. Ultimately, this analysis offers valuable insights into the complexity of noise and the multiple levels on which it operates.