Also included are records of visitors. Forms of documentation include correspondence, memoranda, budgets, and reports, including progress reports. Forms of material include grant applications, correspondence, budgets, progress reports, equipment inventories, lists of recipients of technical reports, and records relating to patents. Apparatus include ear plugs, headbands, headsets, ear insert tips, noise shields, and hearing aids. Forms of documentation include memoranda, reports, drawings, diagrams, photographs, directions for use of the devices, and correspondence.
Correspondence relating to hearing aids extends into the post-war period.
Included here also is anthropometric data, some of which was based on Harvard students. This is a list of folder headings for boxes 1-4. Specific box numbers are not included.