A 5-YEAR LONGITUDINAL STUDY OF 78 CHILDREN (MINIMUM AGE 11 MONTHS) WHO WERE REFERRED TO THE DEPARTMENT OF DEAF EDUCATION AT THE UNIVERSITY OF MANCHESTER, ENGLAND, IS DESCRIBED. THE CHILDREN ALL PRESENTED PROBLEMS RELATED TO SOUND OR LINGUISTICS DEVELOPMENT OR BOTH. AFTER A DESCRIPTION OF THE PHYSIOLOGY OF HEARING AND THE PATHOLOGY OF DEAFNESS, THE METHODS AND VALUES OF THE ELECTROENCEPHALOGRAM, THE GALVANIC SKIN RESPONSE, AND BEHAVIORISTIC TESTS OF HEARING ARE EXPLAINED. CASE HISTORIES ARE PRESENTED FOR PERIPHERALLY DEAF, APHASIC AND DYSPHASIC, MENTALLY DEFECTIVE, CEREBRAL PALSIED, AND VISUALLY HANDICAPPED CHILDREN. INSTRUCTIONS FOR TEACHERS AND PARENTAL GUIDANCE ARE ALSO COVERED. RESULTS OF THE TESTS OF HEARING ARE PRESENTED. PHOTOGRAPHS AND FIGURES ILLUSTRATE THE TEXT. A BIBLIOGRAPHY LISTS 90 ITEMS. THIS DOCUMENT WAS PUBLISHED BY THE MANCHESTER UNIVERSITY PRESS AND IS AVAILABLE FROM THE VOLTA BUREAU, 1537 35TH STREET, WASHINGTON, D.C. 20007. (MW)