A sound classification system for adding and correcting a sound type is disclosed. When the add/correct command processor receives a command to add or correct a sound type, the data in the first database is stored in the second database, and the type adding/correcting device adds the feature of the sound to the first database, and re-calculates the statistical values. Besides, the classifier re-classifies the sample sounds, and the precision calculator calculates a ratio of accurate classification. When the ratio is high, the type adding/correcting device stores, in the feature database, the feature of the sound for which a type is to be added or corrected. When the ratio is low, the second database restores the data back to the first database.