Effect of tone-based sound stimulation on balance performance of normal subjects: preliminary investigation.

Sound is known to affect the human brain, hence sound or music therapy is sometimes used to improve a subject's physicaland mental health. In this study, the effects sound stimulation has on balance were investigated by means of computerizeddynamic posturography tests performed with eyes closed on an unstable surface using a CAPS® system, exceeding theInternational Society for Posture and Gait Research (ISPGR) recommended metrological performance standards. Subjectswere tested without listening to any music (baseline), listening to “pure music”, and listening to the same music with differenttones embedded into it (one for each key). We found that different subjects react differently to different tones. Music alonedid not have a statistically significant effect on balance compared to the baseline, but the “best” tone significantly improvedbalance compared to the baseline or the “pure music” conditions. Furthermore, the “worst” tone reduced the balancecompared to “pure music”, but the reduction was not statistically significant relative to the baseline. The results thereforeindicate that, at least relative to balance performance, the tone-based sound stimulation we investigated is effective andinherently safe, but that tone selection depends on the individual subject.