1. A method comprising: receiving accelerometer data indicating a change in a motor vehicle velocity; processing the accelerometer data to determine a preliminary crash detection decision indicating that the motor vehicle may have experienced a crash based on an accelerometer crash pulse; processing at least one of microphone data obtained from a microphone during a time associated with the motor vehicle crash to determine a sound amplitude measurement data and velocity data of the motor vehicle obtained during the time associated with the motor vehicle crash; comparing the accelerometer crash pulse to at least one of the sound amplitude measurement data and the velocity data; and determining the motor vehicle has been in a crash based on the comparing of the accelerometer crash pulse to at least one of the sound amplitude measurement data and the velocity data.