Effects of Meter Complexity and Sound Intensity of the Vigor of Synchronous Walking

Much research has focused on identifying the qualities and conditions of music that evoke the sensation of “groove”— the pleasurable human urge to move in time to music. However, aside from this and a prior companion study, no investigations have explored the potential groove effect of simple metronome meter-rhythms on repetitive physical activities, including that of walking. Additionally, while a few studies have examined the effect of music sound intensity during walking, auditory stimuli have not been compared with the silent walking condition at equivalent cadence. In Shay (2023a), a range of “basic meters” varying in monotonicity and complexity were created using an accenting metronome, that placed a different tonal accent on the first beat of each repeating measure created. Quadruple meter with a corresponding 4/4 time signature elicited the longest synchronous step lengths and proportionately fastest walking speeds. Additionally, the stimulation of music a metronome was found to increase linearly with increasing sound intensity (Shay, 2022b). With the same participant and test track at a confirmed synchronous walking tempo of 120 bpm, the current investigation aimed to validate and expand upon previous findings by introducing another level of metronome meter complexity (basic quadruple meter with secondary third-beat accenting) in an integrated design across a wider range of sound intensity — 59 dB (faint) to 87 dB (moderately loud). The order of increasing participant vigor elicited by the four stimulus conditions studied was: nearly monotonic basic 10/4 metronome meter < basic 4/4 metronome meter < secondary accented 4/4 metronome meter < familiar–enjoyable 4/4 single-genre music. This sequence represents the order of decreasing meter monotonicity and increasing meter-rhythm complexity overall. Over the intensity range studied, walking speed increased similarly (approximately 11%) with increasing intensity for all stimuli, suggesting that intensity serves as a modulator of the auditory stimulus. At higher intensities, all conditions of music and metronome meter produced more walking speed than the 120 spm silent walking condition. These results align with prior findings, demonstrating that at equivalent sound intensities and synchronous walking tempos, reducing the monotonicity of the meter or increasing the complexity of the meter-rhythm progressively enhances sensorimotor stimulation. Furthermore, sound intensity modulates the level of the stimulus vigor produced. These findings have practical implications for walkers, runners, and other repetitive exercise and sports domain activities. Additionally, they provide insights into the auditory coupling with the human motor system and may hold potential for applications in cued-rehabilitation of human gait disorders.