Occasionally symbols are added, removed, or modified by the International Phonetic Association. As of 2008, there are 107 distinct letters, 52 diacritics , and 4 prosody marks in the IPA proper. Contents 1 History 2 Description 2.1 Letterforms 2.2 Symbols and sounds 3 Usage 3.1 Educational initiative 3.2 Use 3.2.1 Linguists