Vowel whose quality does not change over the duration of the vowel is called a monophthong. Monophthongs are sometimes called "pure" or "stable" vowels. A vowel sound that glides from one quality to another is called a diphthong, and a vowel sound that glides successively through three qualities is a triphthong. All languages have monophthongs and many languages have diphthongs, but triphthongs or vowel sounds with even more target qualities are relatively rare cross-linguistically. English has all three types: the vowel sound in "hit" is a monophthong , the vowel sound in "boy" is in most dialects a diphthong , and
Seizure types of seizures can be attributed to Babylonian scholars who inscribed their medical knowledge into stone tablets known as the "Sakikku" (meaning "All Diseases"). This dates from the reign of the Babylonian king Adad-apla-iddina of the Second Dynasty of Isin - estimated to be between 1067 and 1046 BC. Many types of seizures are described, each attributed to a certain demon or departed spirit and given a prognosis. Notes Further reading Seizure types Seizure types most commonly follow the classification proposed by the International League Against Epilepsy (ILAE) in 1981. Distinguishing between seizure types is important since different types of seizure