Hearing aid is as important as tympanoplasty in regard of hard of hearing problem. With the growing number of demand and supply, the hearing aid became to receive more attention in selection and application. During the past one year and four months, from May 1971 to September 1972, the Speech & Hearing Center of Severance Hospital had 90 cases of hearing aid selection and evaluation. With this materials clinical analysis was done on age distribution, pure tone and speech audiometry and also an analysis of selected hearing aids was done.