Jet noise data are acquired in three different forms: static, flight, and simulated forward flight. Often data must be transformed from one type to one of the other two. A number of studies exist defining the relationship between these three types of measurements. These studies are deficient because they do not explicitly consider the jet noise source characteristics or do not clearly distinguish between mean square pressure, power spectral density, and one-third octave band sound pressure level measurements. In the current study, the relationships between static, subsonic flight, and subsonic simulated forward flight one-third octave band sound pressure level measurements were defined.