The victims bill of rights does say specifically that victims have a right to testify either behind a screen or through some other device, like a video. When I visited your centre you had a special room that was very child friendly with hidden video cameras in it. You get statements from children right after the event of whatever has happened to them. That's the sort of thing you're talking about, I assume, and allowing that to be used in the courtroom.
What other kinds of testimonial aids are you referring to? Can you give some examples?