This is an interesting position paper by Dr. Jamie Ward at Department of Psychology, University of Sussex, UK. about the vOICe. The paper is backed by a small survey too. Dr. Ward is trying to answer the following3 questions.
(1. What do potential blind users want out of a visual-to-auditory device?

2. How do different operating characteristics of the device affect objective
performance?

3. What are the subjective experiences of expert users of the device?

You can read the paper by clicking here.