Embodiments of the invention are related to managing noise in sensed signals in implantable medical devices, amongst other things. In an embodiment the invention includes a method for processing electrical signals obtained from a patient including gathering a first set of electrical signals using an implantable medical device, filtering to provide a second set of electrical signals, the second set including frequencies above a threshold frequency, and estimating the amount of noise present in the first set of electrical signals based on the magnitude of the second set. In an embodiment, the invention includes a medical device configured to gather a first set of electrical signals, filter the first set to provide a second set of electrical signals including frequencies above a threshold frequency, and estimate the amount of noise present in the first set based on the magnitude of the second set. Other embodiments are also included herein.