Consonant chords stimulate higher EEG gamma activity than dissonant chords.

We examined the perceptions of consonant and dissonant chords to test auditory coherent percepts that are related to gamma oscillation. Consonant chords have coherent auditory properties due to the physical relationships of their components, in contrast to dissonant chords. EEGs were measured on 18 subjects with no musical expertise while they listened to consonant chords, dissonant chords, and single-note sounds and counted the number of single tones they heard. Induced gamma band activity was observed over the right brain hemisphere 170ms after the onset of stimuli. The induced gamma activity was significantly increased while listening to consonant chords as compared to dissonant chords. Our results suggest that the neural activity of the gamma frequency bands may reflect an auditory coherent percept generated from physical relationships of sounds.