This article reports the two extensive aircraft noise annoyance surveys subsequently carried out among residents in the vicinity of Zurich Airport in 2001 and 2003 in order to update and validate existing exposure-effect relationships for aircraft noise and annoyance in Switzerland. Logistic and polynomial approximations of the exposure-annoyance relationships for both the years 2001 and 2003 are presented for the L(dn), L(den), and L(A,eq24) noise metrics. The results confirm other recently published international research and provide further evidence that community annoyance due to aircraft noise has increased over the past decades. Between the two survey years, a considerable amount of early morning and late evening flight operations have been relocated to use an other runway than before; thus both the effects of a recent step decrease and recent step increase on the exposure-annoyance relationship could be investigated. Residents that experienced a step increase elicited a quite pronounced over-reaction of annoyance which correlated with the magnitude of the change. Two logistic regression models are provided to forecast the effects of changes in exposure during shoulder hours in the early morning and the late evening.