Our Sensory Disabilities Research Unit has worked on this. Contact Dr Helen Petrie (H.L.Petrie) at UH phone 01707-285058 Fax 01707-285059 Sallie Cooper Disabled Students Officer University of Hertfordshire College Lane Hatfield Herts AL10 9AB Direct line: 01707-284454 Fax: 01707-284993 Minicom: 01707-284000 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%