In linguistics, stress is the relative emphasis that may be given to certain syllables in a word, or to certain words in a phrase or sentence. Stress is typically signaled by such properties as increased loudness and vowel length, full articulation of the vowel, and changes in pitch. The terms stress and accent are often used synonymously, but they are sometimes distinguished, with certain specific kinds of prominence (such as pitch accent, variously defined) being considered to fall under accent but not under stress. In this case, stress specifically may be called stress accent or dynamic accent.