Long-term evolution of noise annoyance depends on the type of transportation noise - what are the main drivers for the observed trends and their differences?

Transportation noise annoyance has been investigated in a widely standardized way over the last decades, which allows studying the evolution of exposure-response relationships over time. A comparison reveals an increase of high annoyance in recent studies for railway and especially aircraft noise, compared to rather stable relationships for road traffic noise. Yet the reasons for these disparate developments remain only little explored, particularly for railway noise. In this contribution, potential explanations for the observed divergences are discussed, namely changing values and expectations in society, changing semantics of words used in survey instruments, changes in the attitude towards the different types of traffic, and changes in exposure strength and characteristics. On that basis, considerations are made about the suitability of noise annoyance as a noise effect informing noise limits.