The Speech-to-Song Illusion

Abstract

Chapter 10 begins with the author’s discovery that a phrase she had enunciated—“Sometimes behave so strangely”—when presented repeatedly, came to be heard as sung rather than spoken. This illusion is presented as a sound example. It shows that speech can be perceptually transformed into song without altering the sounds in any way, or by adding any musical context, but simply by repeating a phrase several times over. The speech-to-song illusion, as Deutsch named it, has no obvious explanation in terms of current scientific thinking about the neural underpinnings of speech and music. Many researchers believe that speech and music are each analyzed in independent modules, based on their physical characteristics. This view was supported by studies of stroke patients, some of whom lost their power of speech while their musical abilities remained intact, whereas others lost aspects of musical ability while their speech remained normal. In contrast, philosophers and composers throughout the ages have argued that a continuum extends from ordinary speech at one end to song at the other, with emotional and heavily intoned speech in between. Some recent brain-scanning studies have supported the idea that speech and song are subserved by the same circuitry, while others have shown that song involves more brain regions than speech. Evidence for these different views are currently being debated, but the exact explanation for the speech-to-song illusion remains a mystery.