The twelve harmonic intervals possible within an octave and reproduced octave in both a high register and low register (geometric mean respectively: 1,510 and 185 Hz) over a three-octave range were judged by 43 university students using a semantic differential.
The semantic differential scale was made up of 30 bi-polar adjective rating scales chosen from descriptions of musical interval expressiveness developed by music theorists. Factor analysis of the students’ responses grouped the scales along three factors: emotional evaluation, activity and potency.
The first two factors proved to be important in interval discrimination and to have the same trend; the latter was less important and resulted in neutral scores. Analysis made with ANOVA revealed a significant Register x Interval interaction for the thirds, the perfect fourth, the sixths and the minor seventh. For these, a high register presentation tended to polarise the bichord perception positively, while with a low register presentation the bichords tended to be perceived as neutral or moderately negative. For intervals with a clear harmonic connotation of consonance or dissonance (octave, fifth, seconds, augmented fourth and major seventh), however, profiles were univocal.
The influence of register on the students’ semantic differentiation of the intervals was significant: low register bichords were evaluated more negatively emotionally in comparison to high register bichords. Dissonant bichords were clearly perceived as more negative, unstable and tense than consonant ones which were evaluated within a neutral zone. Musical expertise was not a significant factor in the evaluation of the intervals. Mode proved to be significant on seven scales with a weak effect. Gender proved to influence interval evaluation in that females responded with a greater polarisation of scores and greater perception of a sense of activity and tension.