Abstract: A system for recording one or more parameters of a patient, comprising a peri-tracheal microphone, a memory, a controller, a power source, and a housing, is disclosed. The microphone provides a signal indicative of at least quiet breathing of the patient. The memory stores information derived from the signal indicative of at least quiet breathing of the patient. The controller writes the information into the memory. The power source supplies electrical energy to at least one of the microphone, the memory, or the controller. The housing contains one or more of the controller or the memory or the power source, and is coupled to a non-peri-tracheal portion of the patient's body such that the housing moves substantially in concert with said non-peri-tracheal portion of the body. Information stored in the memory may be assessed to characterize the state of the patient, possibly including aspects of breathing while awake or asleep.