Design and validation of an auditory biofeedback system for modification of running parameters

Real-time auditory feedback during sports activities is becoming increasingly popular in view of opportunities for monitoring and movement (re)training in ecological environments. However, the design of an effective feedback strategy is difficult. In this paper, we present a methodical approach to the design of an auditory feedback strategy for running gait modification of recreational runners, using distortion of a musical baseline. First tests were conducted to select the best performing auditory distortion signal in terms of clarity and level perception, and to derive the relative perception curve. This was found to be pink noise with an exponential response curve. Further tests were carried out to determine the just noticeable difference of this signal in actual running conditions. Finally, validation tests were performed to examine if the real-time auditory biofeedback, combined with music, could alter the runner’s steps per minute (SPM) during treadmill-based running. The results show that our sonification strategy can alter the mean running SPM in a clear and non-disturbing way, and that our noise-based continuous feedback approach performs better than standard verbal instructions. Even though some of the participants did not respond effectively to the feedback, a large majority of the participants rated the feedback system as pleasant and indicated that they would use such system to improve their running style.