Some mild, moderate, and moderately severe-hearing impaired children have poor language and educational problems despite comparatively good hearing. We studied 30 mild, moderate, and moderately severe hearing-impaired children cared for at Showa University and Jiseikai Hospitals. Their ages ranged from 3 to 14 years and average hearing from 35.0 dB HL to 68.8 dB HL. Our findings were as follows: (1) The average age of suspected hearing problem onset was 2 years 10 months. On the average, delayed diagnosis was made at 4 years 2 months and children were fitted with hearing aids at 5 years 3 months. (2) Over 25% them wore hearing aids infrequently. (3) Language delay was observed in 14 of 24 children examined using the WISC-III test. Many wore hearing aids infrequently and exhibited inadequate oral communication in Japanese due, for example, to deaf parents or children educated overseas. (4) According to a questionnaire, many mothers usually talked to the children aware of their hearing condition. But almost mothers of children with delayed development could not teach children if they couldn't hear, and only repeated same words for children's clarification, e.g., "Pardon?". It is important to detect hearing impairment in children as early as possible. Guidance by specialists and communication training are very important, especially for children who are mild, moderate, and moderately severe hearing-impaired.