To facilitate the use of operant audiometry with low functioning children (psychotic, severely retarded, or multiply handicapped), a procedures manual was developed containing definitions of terms, instructions for determining reinforcers, physical facilities and equipment needs, diagrams, component lists, and technical descriptions. Development of the method began with the child brought into the testing room by the trainer who assisted the child in pushing a button when a tone was presented. Reinforcements were presented after each push until the child was responding appropriately; conditioning occurred at different frequencies and with changing reinforcement schedules, and the child was conditioned to wear earphones. The final hearing test was then conducted. Instructions are provided for the trainer who attempted to consider possible reactions by the subjects and provided for fading out assistance; directions for the examiner, who operated the equipment, are also included. An auxiliary program using a tone-light combination is included for children who did not respond to the above procedures. (JB)