Hearing function can affect communication skills and especially speech and language abilities.As a result, most of the attempts in behavioral audiometry have focused on the improvement and rectification of the techniques for hearing evaluations of the infants and children.Crib-O-gram and the methods suggested by northern & Downs are some of the mentioned protocols.For years a significant advance for evaluating hearing sensitivity of children have been taken place. say, behavioral visual audiometry, VRA, TROCA and play audiometry. some studies also have been performed regarding to the use of BOA technique in mental retarded children and its success in evaluating hearing sensitivity in such children.other protocols use rewarding techniques for reinforcing child's responses which have been demonstrated to be success in the evaluation.In addition,by comparing the results of frequency and intensity discrimination (by means of Luescher test), the changes in the resonance frequency of the outer ear and loudness comfortable level(LDL), one can study the process of hearing development in children.