Telephone speech comprehension is being evaluated in six prelingually deaf children implanted with the Nucleus 22 prosthesis fitted with the Speak strategy. All of them have had at least 1.5 years of experience with their implant. When the tests began, they had already had at least 2 months' experience with the same map in their speech processor. The children were trained in the use of the telephone as part of the rehabilitation program. None of them used it regularly but as a game that they found very entertaining. A special battery, the Bate-fon (batería para teléfono = telephone battery), was designed for training and evaluation purposes. It includes the five Spanish vowels in isolation, diphthongs, onomatopoetic animal voices, two-syllable, and three-syllable words. The tests were administered 1.5-2 years after the switch-on of their speech processor. Standard acoustic telephone coupling was used. The speech material was presented to the child on colored cards. Stimuli were presented twice. Children were informed when the response was incorrect. Averaged results indicated that the percentages of correct responses for all the speech material increase in the second presentation. All children have shown some degree of telephone communication abilities. As a result of the training, some of the children are using the telephone to communicate with their families.