Sound classification based on empirical data, electrophysiological indicators, and behavioral responses are becoming critical in understanding the relationship between sound and emotions. This study aimed to combine electrophysiological and behavioral data to obtain information about emotions elicited by sound stimuli — dissonant and harmonic chords. The results indicated that, at the behavioral level, dissonant chords are significantly more often perceived as negative, while harmonic chords are associated with positive emotions. Additionally, the reaction time for dissonant chords is significantly longer than harmonic ones. At the level of brain information processing, the literature identifies temporal windows in the region of late negativity (N5) when determining regions of interest. However, using permutation statistics, no significant differences were found between the brain responses to harmonic and dissonant chords. Therefore, it can be concluded that using only one type of indicator is insufficient for characterizing the emotional reaction to sounds. Integrating multiple indicators to provide a more comprehensive and accurate understanding of emotional reactions to auditory stimuli is necessary. Moreover, the use of modern data processing tools helps to avoid errors associated with p-hacking practices.