1. Summaries of the change in EPNL of the N+2 aircraft relative to their respective reference aircraft are shown in Figure 4 and Figure 5 for the approachand sideline conditions, respectively. The N+2 aircraft offer substantial noise reduction over the corresponding reference aircraft for both operating conditions. The introduction of ITD noise reductiontechnologies yields about 0.5-1 EPNdB additional reductionineachcase.
2. Forcontrolcases,segmentsassociated withthereferenceaircraft(IDs1-4)werepaired withthemselvesatthetmaxextractiontimeonly. Theabovesegmentpairingschemeresultedin106uniquepairings. Eachpairingwaspresented to test subjectstwice, forward (A/B) and backward (B/A), to eliminate presentationorder bias. The specific pairings are provided inSectionV.A.
3. The psychoacoustic tests were performed in the NASA Langley Research Center (LaRC) Exterior Effects Room (EER)6during the period November-December 2015 in accordance with an approved NASA LaRC Institutional Review Board review of a human subject test application entitled "Environmentally Responsible Aviation Psychoacoustic Test - 2015" (eRapt-15).