**Conflict of interest**

*Visual Impairment and Blindness - What We Know and What We Have to Know*

space (fourth level). The comparison of overall spatial performance before and after the training with a dedicated assessment battery indicated that the ABBI device is effective in improving spatial skills in an intuitive manner (see **Table 1** for a summary of results), confirming that in the case of blindness perceptual development can be enhanced with naturally associated auditory feedbacks to body movements [148]. Moreover, the validation of the ABBI device demonstrated that the early introduction of a tailored audio-motor training could potentially prevent spatial

*One year follow-up of the ABBI group (T2-T0). In order to evaluate the effects within groups, two-tailed t-tests assuming equal variances were performed between groups at baseline (T0) and post-training period (T1). Changes in the outcome measures were then calculated between baseline (T0) and post-training period (T1) in the ABBI training and classical training group (ΔΑ and ΔC), and between baseline (T0) and follow-up period (T2) in the ABBI training group (ΔΑ2). Data are presented as mean and standard deviation. The stars indicate the statistical significance of the corresponding t-test of the score difference (\*p < 0.05; \*\*p < 0.01; \*\*\*p < 0.001). Table readapted* 

Visual experience is deemed to be fundamental for the acquisition of spatial competence; indeed, visually impaired children tend to manifest impairments in spatial and locomotor skills, causing a general developmental delay. The hearing sense can be boosted since an early age to foster compensatory mechanisms for the development of spatial perception, principally because compared to touch it can provide distal information [150]. There is evidence that multisensory training based on the action-perception link can improve spatial abilities in visually impaired children and

prevent the risk of developmental delays and social exclusion [148, 149, 151].

We would like to thank all the children and parents for their willing participation in our studies and the Unit for Visually Impaired People (UVIP) members for

developmental delays in visually impaired children [149].

*Score difference (Δ) after 12 weeks training (T1-T0).*

their passionate work on visually impaired individuals.

**260**

**5. Conclusions**

*from [148].*

**Table 1.**

**Acknowledgements**

The authors declare no conflict of interest.
