Pitch properties of chords of octave-spaced tones

Abstract

Listeners were presented with simultaneities of 1,2,3, or 4 octave-spaced (Shepard tones). In Experiment 1, they were asked how many tones they heard in each chord (its multiplicity). In Experiment 2, they heard a chord followed by a tone, and were asked how well the tone went with the chord; this resulted in a tone profile for each chord. In Experiment 3, they heard successive pairs of chords, and were asked to rate their similarity. The experiments may be regarded as octave-generalized versions of experiments reported in Parncutt (1989). Results were modelled by adjusting and extending a psychoacoustical model for the root of a chord (Parncutt, 1988). The model predicts the multiplicity of a chord, the salience (probability of noticing) of each tone in a chord, and the strength of harmonic relationships between chords (pitch commonality). Implications for the theory of roots, implied scales, and harmonic relationships are discussed.