Phonological but not semantic influences on the speech-to-song illusion

In the speech to song illusion, a spoken phrase begins to sound as if it is being sung after several repetitions. Castro et al. (2018) used Node Structure Theory (NST; MacKay, 1987), a model of speech perception and production, to explain how the illusion occurs. Two experiments further test the mechanisms found in NST—priming, activation, and satiation—as an account of the speech to song illusion. In Experiment 1, words varying in the phonological clustering coefficient influenced how quickly a lexical node could recover from satiation, thereby influencing the song-like ratings to lists of words that were high versus low in phonological clustering coefficient. In Experiment 2, we used equivalence testing (i.e., the TOST procedure) to demonstrate that once lexical nodes are satiated the higher level semantic information associated with the word cannot differentially influence song-like ratings to lists of words varying in emotional arousal. The results of these two experiments further support the NST account of the speech to song illusion.