Purpose: Using the printed-word paradigm with eye tracking, this study conducted three experiments to examine (a) how multiple words in spoken overlapping ambiguity strings (OASs) are activated, (b) how word frequency influences the word segmentation of spoken OASs, and (c) whether the multiple words in spoken OASs are activated competitively or independently.
Method: In this study, participants listened to a four-character spoken OAS (ABCD) and were presented with a visual display composed of a semantic associate of the "middle word" (BC; Experiments 1 and 2) or the "left word" (AB; Experiment 3) and two distractors. In Experiment 1, the word frequency of the middle words was manipulated to be higher than that of the neighbor words. In Experiment 2, the word frequency of the middle words was manipulated to be either higher or lower than that of the neighbor words. In Experiment 3, participants listened to either spoken OASs (ABCD) or spoken unambiguous strings (ABEF).
Results: In Experiment 1, we observed a significant semantic competition effect; that is, more fixations fell on the semantic competitors than on distractors, suggesting that the semantic information of the middle words in the spoken OASs was activated. In Experiment 2, the semantic competition effect was only observed in the high-frequency condition and was absent in the low-frequency condition. In Experiment 3, the results showed significant semantic competition effects for the left words under both conditions, and the observed effect was similar between the ambiguity condition and the control condition.
Conclusions: These findings show that multiple words in spoken OASs are all activated and the activation level is modulated by word frequency. In addition, multiple words in the spoken OASs may be processed independently during spoken comprehension.