It is questionable whether stable-condition exposure–response guidelines can be applied effectively in changing noise contexts. This study examines aircraft noise response under changing exposure scenarios at Vietnam’s two busiest airports: Noi Bai (NB) and Tan Son Nhat (TSN). At NB, flight operations increased following the opening of a new terminal in 2014. Surveys conducted before and after revealed an initial increase in annoyance (%HA), followed by a return to pre-expansion levels despite rising noise, indicating a fading change effect over time. Conversely, at TSN, noise exposure sharply declined during the 2020 COVID-19 pandemic; however, annoyance increased, peaking again in 2023 despite a decrease in noise level. Structural modeling revealed that non-acoustic factors—such as housing quality, stress, and noise sensitivity—significantly moderated the level of annoyance. At NB, higher sensitivity amplified reactions to increasing noise, but had diminishing effects at higher exposures. At TSN, poor housing and pandemic-related stress were key predictors of annoyance. These results suggest asymmetric responses: overreaction in NB and underreaction in TSN, deviating from predictions under stable conditions. These findings emphasize that airport noise policy must account for temporal shifts, non-acoustic influences, and regional context, particularly in fast-urbanizing areas.
Nguyen et al. (Wed,) studied this question.