Variability of sound quality metrics for different aircraft types during landing and takeoff

The capacity of airports is limited due to the negative community response to noise. Traditional metrics, such as the A-weighted maximum sound pressure level (Lp;A;max), indicate the overall noise generated by an aircraft flyover but do not provide any information on tonal components or frequency variations in time that are known to affect annoyance. In this work 158 flyovers recorded at Amsterdam Schiphol Airport are analyzed in terms of sound quality metrics (SQM), loudness, roughness, tonality, sharpness and fluctuation strength. The recordings include landing and takeoff operations of 15 different aircraft types. The variability of the levels of the SQM are assessed per aircraft type. Possible correlations between the SQM and airframe and engine characteristics are investigated and empirical expressions for the loudness and roughness are formulated. The Effective Perceived Noise Level (EPNL) and the Psychoacoustic Annoyance Metric (PAmod) are calculated for each flyover. The two metrics show a high correlation between them and this result is further investigated using listening tests. The listening tests show that tonality has a high importance in annoyance, however, its influence in PAmod was found to be small.