Vowels and consonants can be thought of as the segments of which speech is composed. Together they form syllables, which when combined make up utterances. Superimposed on the syllables are other features known as suprasegmentals. The principal suprasegmental features are length, pitch, and intonation. Variations in length are also usually considered to be suprasegmental features. Pitch changes due to variations in laryngeal activity can occur independently of stress changes. The pitch pattern in a sentence is known as the intonation. These features are independent of the categories required for describing segmental features (vowels and consonants), which involve airstream mechanisms, states of the glottis, articulation, and formant frequencies. They do, of course, convey information about the speaker's age, gender, emotional state, and attitude toward the topic under discussion[14].
