For the interpretation of archaeological geophysical data as archaeological features, it is essential that the recorded anomalies can be clearly delineated and analyzed, and therefore, care must be taken to obtain the best possible data. However, as with all measurements, data are degraded by unwanted components, or noise. This poster clarifies the terminology, discusses the three major sources of noise (instrument, use of instrument, external). But soil has to be considered also as the origin of another type of noise rarely described: for archaeological structures to be detectable, archaeo-geophysicists know that there must be one or more contrasts in physical properties between the soil and the structures. But much more rarely are considered two other factors: the spatial structure of the soil and/or its surface condition. However, these intrinsic factors greatly influence the detection of buried heritage. These factors will not have the same consequences depending on the types of geophysical methods used and even depending on the type of device used.