The paper analyses issues in the hearing assessment of multihandicapped deaf-blind children. The experiences of the authors as consultants to centers for deaf-blind children are briefly noted. Advantages and disadvantages are considered for two basic approaches to hearing assessment: the electrophysiologic in which electricity from neural generators in the brain is recorded, and behavioral, in which children produce either conditioned or unconditioned responses. Among electrophysiologic approaches noted are immittance audiometry and auditory brainstem response. Procedures within behavioral assessment are reviewed, and the following aspects discussed: stimulus, waiting posture, response, reinforcement, controls, and the use of a multisensory reinforcement box. Guidelines for establishing conditioning programs with the box are offered. (CL)