Sonification as a possible stroke rehabilitation strategy

The possibility of using auditory information supplementary to visual feedback in order to inform patients about movements of their impaired arms is a promising new method, referred to as “sonification”.  This is way too new and novel to get to your rehab center for another 100 years.

Sonification as a possible stroke rehabilitation strategy

Daniel S. Scholz1, Liming Wu1, Jonas Pirzer1, Johann Schneider1, Jens Rollnik2, Michael Großbach1,
Eckart Altenmüller1*
1 Institute of Music Physiology and Musicians' Medicine, University of Music, Drama and Media,
Hannover, Germany
2 BDH-Klinik, Hessisch Oldendorf, Germany
*Corresponding author:
Eckart Altenmüller,
University of Music, Drama and Media
Institute of Music Physiology and Musicians' Medicine
Emmichplatz 1
30175 Hannover
Germany
eckart.altenmueller@hmtm-hannover.de

Abstract
Despite cerebral stroke being one of the main causes of acquired impairments of motor skills
worldwide, well-established therapies to improve motor functions are sparse. Recently, attempts
have been made to improve gross motor rehabilitation by mapping patient movements to sound,
termed sonification. Sonification provides additional sensory input, supplementing impaired
proprioception. However, to date no established sonification-supported rehabilitation protocol
strategy exists.
In order to examine and validate the effectiveness of sonification in stroke rehabilitation, we
developed a computer program, termed “SonicPointer”: Participants' computer mouse movements
were sonified in real-time with complex tones. Tone characteristics were derived from an invisible
parameter mapping, overlaid on the computer screen. The parameters were: tone pitch and tone
brightness. One parameter varied along the x, the other along the y-axis. The order of parameter
assignment to axes was balanced in two blocks between subjects so that each participant performed
under both conditions. Subjects were naive to the overlaid parameter mapping and its change
between blocks. In each trial a target tone was presented and subjects were instructed to indicate its
origin with respect to the overlaid parameter mapping on the screen as quickly and accurately as
possible with a mouse click. Twenty-six elderly healthy participants were tested. Required time and
two-dimensional accuracy were recorded. Trial duration times and learning curves were derived.
We hypothesized that subjects performed in one of the two parameter-to-axis–mapping better,
indicating the most natural sonification.
Generally, subjects' localizing performance was better on the pitch axis as compared to the
brightness axis. Furthermore, the learning curves were steepest when pitch was mapped onto the
vertical and brightness onto the horizontal axis. This seems to be the optimal constellation for this
two-dimensional sonification.