THE SPEECH INTERFERENCE EFFECTS OF AIRCRAFT NOISE

For various aircraft flyovers, speech intelligibility scores and calculations of AI (Articulation Index) were obtained as functions of time. These data were then used to establish the relation between AI and intelligibility for time-varying noise. A similar relation was also obtained for steady-state simulated jet noise. A comparison of the two relations showed that for a given AI, the time-varying noise provided less masking than the steady-state noise. The difference found between the two relations cautions against the use of relations established for steady-state noise to predict intelligibility scores that might be obtained with time-varying noise. The aircraft flyovers employed in the intelligibility tests were also presented to listeners who were asked to rate them in terms of their acceptability in the home. Using a rating scale having the categories 'of no concern,' 'acceptable,' 'barely acceptable,' and 'unacceptable,' judgments were obtained in three listening situations: (1) in the presence of radio-TV speech; (2) in the absence of speech; and (3) in the presence of telephone speech. (Author)