The effect of low-frequency equalisation on preference and sensorimotor synchronisation in music

Equalisation, a signal processing technique commonly used to shape the sound of music, is defined as the adjustment of the energy in specific frequency components of a signal. In this work, we investigate the effects of equalisation on preference and sensorimotor synchronisation in music. A total of 21 participants engaged in a goal-directed upper body movements in synchrony with stimuli equalised in three low-frequency sub-bands (0-50, 50-100, and 100-200 Hz). To quantify the effect of equalisation, music features including spectral flux, pulse clarity, and beat confidence were extracted from seven differently equalised versions of music tracks-one original and six manipulated versions for each music track. These music tracks were then used in a movement synchronisation task. Bayesian mixed-effects models revealed different synchronisation behaviours in response to the three sub-bands considered. Boosting energy in the 100-200 Hz sub-band reduced synchronisation performance irrespective of the sub-band energy of the original version. An energy boost in the 0-50 Hz band resulted in increased synchronisation performance only when the sub-band energy of the original version was high. An energy boost in the 50-100 Hz band increased synchronisation performance only when the sub-band energy of the original version was low. Boosting the energy in any of the three sub-bands increased preference regardless of the energy of the original version. Our results provide empirical support for the importance of low-frequency information for sensorimotor synchronisation and suggest that the effects of equalisation on preference and synchronisation are largely independent of one another.