Otoscopic examination and audiometric tests complement each other for the diagnosis of hearing loss. Objective tests measure the hearing loss at some specific frequencies. Endo- or retrocochlear origin of the deafness is identified thanks to these tests, leading to selection of the most appropriate therapeutic option. In children, behavioral assessment techniques are to be adapted to the patient's age. Information from tympanometry, otoacoustic emissions and possibly auditory brainstem responses, is used to complete the diagnosis. Language skills are also assessed in order to adapt the child's deafness management to his/her actual communication ability.