What is Sonification?

Traditionally, creating sounds from human movements has been the sole privilege of musicians. It is no foreign concept to these talented individuals that the harder one pushes on a violin bow, plucks a guitar string, or blows air into a clarinet the louder and sometimes harsher the produced sound is. Therefore in order to elicit the desired sounds, the musicians have to somehow regulate and control their body movements so that they produce just the right amount of mechanical stimulus to produce sounds. This regulation of body movements is achieved in many cases by attenuating to the pitch that is produced at any specific moment in time. If the pitch is too loud or strong the musician knows that they should not be applying as much force, similarly if it is too quiet the musician recognizes the need to apply more force.

Recently, this type of acoustic real-time feedback of body movements, termed sonification, has gained significant attention as a means to alter and improve body mechanics in fields such as sports and rehabilitation. Several previous studies have demonstrated that a generated tonal pitch that is representative of a person’s current body position can be used as feedback to provide the individual with relevant information regarding their body position. For instance, a runner that exhibits excessive rear-foot heel strike may be provided with a loud noise every time they exhibit the undesired movement. The goal would be to reduce the loudness of the sound as they move further and further away from the heel strike motion until no sound is produced at all. This is but one example of the possible applications of sonification in altering body mechanics. Previous researchers have, however , demonstrated great success in the sports of rowing, swimming, ice skating, biking and basketball. Furthermore, benefits have been seen in rehabilitation of the upper extremity, postural stability and handwriting. However, despite the success and potential that the sonification concept has to offer, there is a relatively limited amount of research regarding its application for rehabilitating gait pathologies.

Therefore the goal of our SONIGait team is to apply the concept of sonification in a way that facilitates gait rehabilitation in individuals with abnormal gait patterns.