Harmonic relations among musical notes affect rhythm judgments for chord sequences

The auditory grouping hypothesis posits that auditory stimuli sharing similar features, such as pitch and spatial location, are more readily perceived as part of a unified auditory event or object. This hypothesis can explain perceptual phenomena where changes in one auditory feature distort judgments of a different feature. For example, the auditory kappa effect illustrates a bias in timing judgments among sequential sounds: those sharing more similar features are perceived as occurring closer in time than more distinct sounds. Higher-level contextual cues also influence perceptual grouping. For example, in music, listeners are better at identifying a target note in a sequence of chords when it is harmonically “distant” (e.g., in a different key) from the rest. The present study investigates whether musical harmony affects perceptual timing (i.e., rhythm) judgments similarly to low-level cues like pitch by exploring auditory kappa effects in sequences of musical chords. Participants judged whether the second chord in each 3-chord sequence was closer in time to the first or third chord. Preliminary data suggest that harmonically similar chords, rated higher in subjective musical “fit,” are perceived as occurring closer together in time than chords with lower harmonic fit ratings.