In linguistics, prosody () is the study of elements of speech, including intonation, stress, rhythm and loudness, that occur simultaneously with individual phonetic segments: vowels and consonants. Often, prosody specifically refers to such elements, known as suprasegmentals when they extend across more than one phonetic segment. Prosody reflects the nuanced emotional features of the speaker or of their utterances: their obvious or underlying emotional state, the form of utterance (statement, question, or command), the presence of irony or sarcasm, certain emphasis on words or morphemes, contrast, focus, and so on. Prosody displays elements of language that are not encoded by grammar, punctuation or choice of vocabulary.
Attributes of prosody In the study of prosodic aspects of speech, it is usual to distinguish between auditory measures (subjective impressions produced in the mind of the listener) and objective measures (physical properties of the sound wave and physiological characteristics of articulation that may be measured objectively). Auditory (subjective) and objective (acoustic and articulatory) measures of prosody do not correspond in a linear way. Most studies of prosody have been based on auditory analysis using auditory scales. Auditorily, the major prosodic variables are:
pitch of the voice (varying between low and high) length of sounds (varying between short and long) loudness, or prominence (varying between soft and loud) timbre or phonatory quality (quality of sound) Acoustically, these prosodic variables correspond closely to:
fundamental frequency (measured in hertz, or cycles per second) duration (measured in time units such as milliseconds or seconds) intensity, or sound pressure level (measured in decibels) spectral characteristics (distribution of energy at different parts of the audible frequency range) Different combinations of these variables are exploited in the linguistic functions of intonation and stress, as well as other prosodic features such as rhythm and tempo. Additional prosodic variables have been studied, including voice quality and pausing. The behavior of the prosodic variables can be studied either as contours across the prosodic unit or by the behavior of boundaries.
Phonology Prosodic features are suprasegmental, since they are properties of units of speech that are defined over groups of sounds rather than single segments. When talking about prosodic features, it is important to distinguish between the personal characteristics that belong to an individual's voice (for example, their habitual pitch range, intonation patterns, etc.) and the independently variable prosodic features that are used contrastively to communicate meaning (for example, the use of changes in pitch to indicate the difference between statements and questions). Personal characteristics that belong to an individual are not linguistically significant while prosodic features are. Prosody has been found across all languages and is described to be a natural component of language. The defining features of prosody that display the nuanced emotions of an individual differ across languages and cultures.
Intonation
Some writers (e.g., O'Connor and Arnold) have described intonation entirely in terms of pitch, while others (e.g., Crystal) propose that "intonation" is a combination of several prosodic variables. English intonation is often said to be based on three aspects:
The division of speech into units The highlighting of particular words and syllables The choice of pitch movement (e.g., fall or rise) The choice of pitch movement and the highlighting of particular words to create different intonation patterns can be seen in the following English conversation:
"That's a cat?" "Yup. That's a cat." "A cat ? I thought it was a mountain lion!" The exchange above is an example of using intonation to highlight particular words and to employ rising and falling of pitch to change meaning. If read out loud, the pitch of the voice moves in different directions on the word "cat." In the first line, pitch goes up, indicating a question. In the second line, pitch falls, indicating a statement— a confirmation of the first line in this case. Finally, in the third line, a complicated fall-rise pattern indicates incredulity. Each pitch/intonation pattern communicates a different meaning. An additional pitch-related variation is pitch range; speakers are capable of speaking with a wide range of pitch (this is usually associated with excitement), while at other times with a narrow range. English makes use of changes in key; shifting one's intonation into the higher or lower part of one's pitch range is believed to be meaningful in certain contexts.
Stress Stress functions as the means of making a syllable prominent. Stress may be studied in relation to individual words (named "word stress" or lexical stress) or in relation to larger units of speech (traditionally referred to as "sentence stress" but more appropriately named "prosodic stress"). Stressed syllables are made prominent by several variables. Stress is typically associated with the following:
pitch prominence (a pitch level that is different from that of neighboring syllables, or a pitch movement) increased length (duration) increased loudness (dynamics) differences in timbre: in English and some other languages, stress is associated with aspects of vowel quality (whose acoustic correlate is the formant frequencies or spectrum of the vowel). Unstressed vowels tend to be centralized relative to stressed vowels, which are normally more peripheral in quality Some of these cues are more powerful or prominent than others. Alan Cruttenden, for example, writes "Perceptual experiments have clearly shown that, in English at any rate, the three features (pitch, length and loudness) form a scale of importance in bringing syllables into prominence, pitch being the most efficacious, and loudness the least so". When pitch prominence is the major factor, the resulting prominence is often called accent rather than stress. There is considerable variation from language to language concerning the role of stress in identifying words or in interpreting grammar and syntax.
Tempo
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