A review of sonification solutions in assistive systems for visually impaired people

PurposeVisually impaired people (VIP) find it challenging to understand and gain awareness of their surroundings. Most activities require the use of the auditory or tactile senses. As such, assistive systems which are capable of aiding visually impaired people to understand, navigate and form a mental representation of their environment are extensively being studied and developed. The aim of this paper is to provide insight regarding the characteristics, as well as the advantages and drawbacks of different types of sonification strategies in assistive systems, to assess their suitability for certain use-cases.Materials and methodsTo this end, we reviewed a sizeable number of assistive solutions for VIP which provide a form of auditory feedback to the user, encountered in different scientific databases (Scopus, IEEE Xplore, ACM and Google Scholar) through direct searches and cross-referencing.ResultsWe classified these solutions based on the aural information they provide to the VIP - alerts, guidance and information about their environment, be it spatial or semantic. Our intention is not to provide an exhaustive review, but to select representative implementations from recent literature that highlight the particularities of each sonification approach.ConclusionsThus, anyone who is intent on developing an assistive solution will be able to choose the desired sonification class, being aware of the advantages/disadvantages and at the same time having a fairly wide selection of articles from the representative class. The motivation behind this paper is to provide an overview of sonification strategies in the context of assistive systems for the visually impaired people.Whilst surveys and reviews which provide in-depth insights into assistive technologies and sonification exist, papers which provide a combined view of these topics are rather lacking.The analysis of the selected papers provides insight regarding the characteristics of different types of sonification strategies in assistive systems for visually impaired people and their suitability for certain use-cases.