Perceived annoyance of Mach-cutoff flight ground signatures compared to common transportation sounds

Abstract

Supersonic flight over land was prohibited by the FAA in 1973 to avoid sonic-booms that cause civilian annoyance. A potential operational solution to sonic-booms over land is Mach-cutoff flight, which in ideal atmospheric conditions, refracts the sonic-boom upwards thus creating an evanescent sound-field below. The goal of this study was to compare the perceived degree of annoyance of the evanescent signatures to common transportation sounds. Mach-cutoff flight stimuli were generated using recordings from NASA’s Farfield Investigation of No-boom Thresholds dataset and transportation sounds were recorded at local interstates, railroads, and airports. Subjective testing was conducted to investigate annoyance and preference using individual comparisons with an absolute scale and multiple comparisons with a relative scale. An ANOVA and a linear-regression model were calculated to analyze the annoyance and preference of the transportation modes. [This research was funded by the U.S. Federal Aviation Administration Office of Environment and Energy through ASCENT, the FAA Center of Excellence for Alternative Jet Fuels and the Environment, Project 42 through FAA Award No. 13-C-AJFE-PSU under the supervision of Sandy Liu. Any opinions, findings, conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the FAA.]Supersonic flight over land was prohibited by the FAA in 1973 to avoid sonic-booms that cause civilian annoyance. A potential operational solution to sonic-booms over land is Mach-cutoff flight, which in ideal atmospheric conditions, refracts the sonic-boom upwards thus creating an evanescent sound-field below. The goal of this study was to compare the perceived degree of annoyance of the evanescent signatures to common transportation sounds. Mach-cutoff flight stimuli were generated using recordings from NASA’s Farfield Investigation of No-boom Thresholds dataset and transportation sounds were recorded at local interstates, railroads, and airports. Subjective testing was conducted to investigate annoyance and preference using individual comparisons with an absolute scale and multiple comparisons with a relative scale. An ANOVA and a linear-regression model were calculated to analyze the annoyance and preference of the transportation modes. [This research was funded by the U.S. Federal Aviation Administra...