While many techniques are known to music creators, the technique of repetition is one of the most commonly deployed. The mechanism by which repetition is effective as a music-making tool, however, is unknown. Building on the speech-to-song illusion (Deutsch, Henthorn, & Lapidis in Journal of the Acoustical Society of America, 129(4), 2245-2252, 2011), we explore a phenomenon in which perception of musical attributes are elicited from repeated, or "looped," auditory material usually perceived as nonmusical such as speech and environmental sounds. We assessed whether this effect holds true for speech stimuli of different lengths; nonspeech sounds (water dripping); and speech signals decomposed into their rhythmic and spectral components. Participants listened to looped stimuli (from 700 to 4,000 ms) and provided continuous as well as discrete perceptual ratings. We show that the regularizing effect of repetition generalizes to nonspeech auditory material and is strongest for shorter clip lengths in the speech and environmental cases. We also find that deconstructed pitch and rhythmic speech components independently elicit a regularizing effect, though the effect across segment duration is different than that for intact speech and environmental sounds. Taken together, these experiments suggest repetition may invoke active internal mechanisms that bias perception toward musical structure.
Keywords: Music cognition; Repetition effects; Sound recognition; Speech-to-song illusion.