hearingthevoice.org/2013/09/09/what-is-it-like-to-hear-voices-a-questionnaire-study/
This is an on-line study by researchers at Durham University, and can be completed anonymously. Much of the research is service user led. I am not a part of the team, but did attend a workshop recently, and they seem like a good lot :) so I thought I would spread the word...