When listening to music and language sounds, it is unclear whether adults recruit domain-specific or domain-general mechanisms to make sense of incoming sounds. Unique acoustic characteristics such as a greater reliance on rapid temporal transitions in speech relative to song may introduce misleading interpretations concerning shared and overlapping processes in the brain. By using a stimulus that is both ecologically valid and can be perceived as speech or song depending on context, the contribution of low- and high-level mechanisms may be teased apart. The stimuli employed in all experiments are auditory illusions from speech to song reported by Deutsch et al. (2003, 2011) and Tierney et al. (2012). The current experiments found that 1) non-musicians also perceive the speech-to-song illusion and experience a similar disruption of the transformation as a result of pitch transpositions. 2) The contribution of rhythmic regularity to the perceptual transformation from speech to song is unclear using several different examples of the auditory illusion, and clear order effects occur because of the within-subjects design. And finally, 3) when comparing pitch change sensitivity in a speech mode of listening and, after several repetitions, a song mode of listening, only a song mode indicated the recruitment of music-specific representations. Together these studies indicate the potential for using the auditory illusion from speech to song in future research. Also, the final experiment tentatively demonstrates a behavioral dissociation between the recruitment of mechanisms unique to musical knowledge and mechanisms unique to the processing acoustic characteristics predominant in speech or song because acoustic characteristics were held constant
