There are many different types of aircraft that fly today. Each type has different features and capabilities. Some aircraft make more noise than others because of the type of engines they have. Also, larger aircraft tend to make more noise than smaller aircraft, though this is not always the case. Proximity to an aircraft affects the volume of sound heard. The volume of noise also depends on the age of the aircraft creating the noise. Newer aircraft have engines and designs that are quieter due to evolved technology. Different engines and airframes have entirely different noises associated with flight.