Sonification as a possible stroke rehabilitation strategy

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 mappings 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 mappings 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–mappings 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.

Enriching footsteps sounds in gait rehabilitation in chronic stroke patients: a pilot study

“…[50][51][52] Furthermore, pairing movements with sounds using instruments (music playing) and sonification of movements have been recently shown to be possible candidates for improvement of motor deficits in acute and chronic patients. [20][21][22][23] Overall, these techniques rely on the establishment of fast auditory-motor mappings as well as auditory feedback processing during music performance (or movement sonification). These mechanisms seem to be responsible for the enhanced neural plasticity of premotor and motor regions encountered in stroke patients after music training.…”

Sonification as Concurrent Augmented Feedback for Motor Skill Learning and the Importance of Mapping Design

“…pitch, loudness, tempo etc.) are clearly more suited to the display of certain kinds of information than others [45,69], but what about certain kinds of movements? Gibson's [70] theory of ecological perception holds that there are invariant relationships between sensory information detected by the organism and the associated event in the environment.…”

Auditory Coding of Reaching Space

“…Movement acoustics has been used in neurorehabilitation dedicated to sensory-motor deficits, for example in the rehabilitation of target-orientated arm movements [12,[31][32][33][34]. Additional work has been realized with guiding-and feedback-acoustics.…”