The Relationship Between Sound Intensity And the Center of Balance

Abstract

Daily activities require the proper coordination between sensory systems, brain integration, and muscular movements. A deviation in any of these systems may slightly or severely disrupt the body’s sensitive homeostatic levels. In this experiment, we investigated the relationship between the sensory processing systems, muscle activity, and controlled balance. By administering increasing sound intensity directly into the subject’s ears, we explored whether there was a correlated deviation from the center of balance. The sense of sight was removed in order to focus on the relationship between auditory stimulation and muscle reactivity. Balance was recorded on a Wii Balance Board, muscle activity was measured using Electromyography (EMG), and sound was regulated through noise canceling headphones. A pulse oximeter was used to detect instantaneous changes in heart rate as a result of the administration of sound at different intensities. Background research has shown evidence that at certain thresholds, sound may influence and alter core balance. We hypothesized that as sound intensity increased, leg muscle activity would increase, and a resulting deviation from the center of balance, measured by path length, would also increase. Our results showed that minimal auditory stimulation increased overall balance resulting in minimal path length movement. However, at and above a sound threshold around 100 mV, an increase in both muscle activity and path length was observed, although no significant relationship was determined. Investigation into how sound intensity and balance are linked must be researched in further detail to determine whether a correlation exists.