Looking at the knife when hearing "map"
When recognizing spoken words, similar sounding words are temporarily considered target candidates. Previous research has shown that words overlapping with a spoken target in phonological onset compete for recognition for as long as the acoustic overlap lasts. Moreover, it has been shown that such phonological competition increases when recognizing words in a foreign language, due to native and non-native words being activated simultaneously. Also, relative to perceiving words in the clear, phonological competition appears to be increased when words are processed in noise. This most likely reflects that listeners interpret the speech signal with more flexibility, maintaining target competitors active for a longer period of time. The present study aimed to investigate the relative importance of the native and non-native mental lexicon when recognizing non-native speech in noise. Eye movements of native Dutch participants were recorded as they listened to English words while looking at a display containing four objects. On filler items, the visual referent depicting the spoken target was present, along with three unrelated distractors. On experimental items, the picture of the spoken target word was absent. Instead, the display featured an English (but not Dutch) phonological onset competitor, a Dutch (but not English) phonological onset competitor and two unrelated distractors. After a preview phase of three seconds, the spoken target was presented via headphones and participants were instructed to indicate whether or not it was visually depicted. On half of the items the spoken word was masked by speech-shaped noise; on the other half, the word was presented in the clear. Participants’ looks to the English and Dutch competitors on experimental items were analyzed, starting at the onset of the spoken target. Unlike previous studies, I did not observe increased fixations to either Dutch or English competitors during early time windows (200-600 ms after word onset). However, significant biases did appear in later time windows (900-1500 ms). In the clear condition, a significant bias for the English onset competitor was found between 900 and 999 ms. A bias for the Dutch onset competitor was found between 1400 and 1499 ms. In the noise condition, I found a bias for the Dutch onset competitor during the same time window as in the clear condition. The bias for the English onset competitor appeared 100 ms later than in the clear condition, and was only significant by subjects (not by items). These results imply that the importance of the non-native mental lexicon decreases once the spoken input is masked by noise. The importance of the native Dutch mental lexicon when listening in noise is comparable to listening in the clear.
Faculteit der Letteren