Advanced operational flight procedures have been proposed to reduce the impact of aircraft operations on community noise. Recent work has led to the development of noise abatement procedures like the delayed-deceleration approach for arrivals. Causes of variation in airport noise monitor network measurements due to departures remain an important source of uncertainty in the development of departure noise abatement procedures. Understanding this variation, found to be up to 20 dB at individual monitors for multiple departures, can be accomplished by analyzing aggregate departure noise and flight procedures so statistically-significant factors that correlate with measured noise can be isolated. This paper aims to identify these factors. Operational flights at Seattle-Tacoma International Airport conducted in March and August of 2019 are examined using a framework that includes ADS-B data from the OpenSky Network, a force balance kinematics model to model aircraft performance, and the Seattle-Tacoma International Airport noise monitor network. Variation in measured departure noise throughout the entire monitoring network is examined as a function of aircraft weight, thrust, velocity, specific energy, and flight path angle. Variables that are found to correlate with increased noise are isolated and can be used to inform the development of future departure noise abatement procedures.