#Speech tempo and pausation
Pauses. The speech continuum is divided into units of different length and hierarchy by means of pauses. It is the main function of a pause to segment connected speech into utterances and intonation groups to delimit one utterance or intonation group from another. Pauses are closely related with tempo: the number and length of pauses affect the general tempo of speech. Phoneticians distinguish 3 main types of pauses: silent pauses, pauses of perception and voiced (or filled} pauses. A silent pause is a stop in the phonation (a stop of the work of the vocal cords, which results in the cessation of sound). Pauses of perception are not a stop in phonation, as there is no period of silence. The effect of a pause is produced by a sharp change of pitch direction, or by variations in duration, or both. Pauses of perception are generally marked by a wavy line which is used at the junction of intonation groups. Voiced pauses have usually the quality of the central vowel [3: (Э)] with or without nasalization [э (m)]. They are used to signal hesitation or doubt and are therefore called hesitation pauses. Pauses are very important constituents of intonation. Besides their segmentative and delimitative functions they also perform a unifying function showing the relations between utterances or intonation groups.