In our day-to-day interactions we often find ourselves in less than advantageous listening conditions. Very seldom do we find that speech is transmitted in complete silence. We find ourselves exposed to accents, regional or foreign, which at times can impede our speech perception abilities. Similarly, the presence of background noise has been found to affect the ability of listeners to process a speech signal regardless of their hearing sensitivity. Therefore, the goal of this study was to determine to what extent neurophysiological indices of semantic processing are affected by native and non-native stimuli under adverse listening situations. By observing the N400 effect, the study measured the effects of native versus foreign accents in the presence of background noise on speech perception for monolingual native speakers of American English. Overall, it has been determined that the neurophysiological indices of semantic processing are affected by native and non-native stimuli under adverse listening situations. The findings of this study suggest that listeners, in the presence of disadvantageous background noise, are more affected in their processing of foreign accented speech than they are in their processing of native accented speech.