#The phonetic nature and types of speech rhythm in different languages.
Rhythm - regularity or periodicity in the occurrence of a particular phenomenon in an utterance. In some languages the recurring phenomena are stresses, in others - syllables. So languages can be characterized either by stress-timed or syllable-timed rhythm. English is considered to be mostly a language with stress-timed rhythm (it presupposes that utterance stress serves as a basis for the rhythmical organization of speech and that stresses segment the speech continuum into units of more or less equal length. These are accentual, or rhythmic units. Hierarchically higher are prosodic units: intonation groups and utterances. Isochrony is a characteristic feature of English rhythm. But perfect isochronism can be realized very rarely, only when definite conditions are fulfilled.
The rhythmic unit is a perceptible unit which can be isolated due to its prosodic features and meanings. Acoustically, rhythm is a complex of variations in frequency, intensity and duration. Since the basis of rhythm is stress, which is a structural acoustic phenomenon, rhythm is a structural acoustic phenomenon too and it is achieved by the same acoustic parameters that produce the effect of stress.
The rhythmic unit is a perceptible unit which can be isolated due to its prosodic features and meanings. Acoustically, rhythm is a complex of variations in frequency, intensity and duration. Since the basis of rhythm is stress, which is a structural acoustic phenomenon, rhythm is a structural acoustic phenomenon too and it is achieved by the same acoustic parameters that produce the effect of stress.