In this study, effects on task performance and annoyance by aircraft and road traffic noise and attitudes towards these noise sources were addressed in a lab-setting. On day 1 of the study, participants performed a 3-back working memory task in silence and with noise samples played over a headphone at four different loudness levels. On day 2, they filled out questionnaires on aircraft/road traffic-related attitudes and noise sensitivity. We hypothesized that attitudes would only affect task response times for noise samples with recognizable sources. For this reason unrecognizable noise samples were generated from the sound characteristics of an Airbus320 flyover and of a road traffic recording and were used next to the original noise samples. Preliminary results showed no differences of attitudes on annoyance. For participants with negative attitudes towards the noise source, response times were rising with increasing loudness levels during recognizable samples, whereas response times decreased during unrecognizable samples when loudness levels rose. For the group with positive attitudes towards the noise source, reaction times seemed fairly stable across conditions. These results indicate that attitudes towards noise sources may mediate the effect of noise on cognitive tasks.