Our speech apparatus is designed in such a way as to allow complex, coordinated movements that result in the multitude of sounds we make (Seikel et al. 2010). However, production of separate, single sounds (as we saw in this previous post) is a very rare phenomenon in speech. Everyday speech comprises utterances that are made up of strings of sounds that are arranged in a linear fashion. We will come back to this notion of speech sound juxtapositions in a future post on articulatory processes.
But speech is not just an arrangement of sounds: if this were the case, language would sound quite monotonous and boring! The source of speech, i.e. breath (coupled at times with voicing), also creates other qualities that go beyond single segments (individual sounds often considered in isolation). These qualities, such as stress and intonation, spread over several segments, spanning syllables and even whole sentences. That is why features such as stress and intonation are often labeled suprasegmental (or prosodic) features: they go above segments (vowels and consonants) and act on longer stretches of speech such as syllables and sentences. In this post, we will be looking at some of these features in detail.
1. Stress
Stress is the result of an increase in the air that is expelled from the lungs, which then causes a rise in the pitch (loudness) of the voice (Ladefoged & Johnson 2011). In the word “coffee” [ˈkɑfi], for example, it is the first syllable [kɑ] that is prominent in pitch, which means it is stressed (Note that the stressed syllable is indicated by a “stress mark” resembling an apostrophe placed before the stressed syllable). In the word “regard”, it is the second syllable (-gard) that receives stress, i.e. it sounds louder than the first syllable (re-). In both cases, the stressed syllables sound more prominent due to 1) an increase in the air from the lungs, and also 2) a lengthened vowel quality (shown with a colon after the vowel symbol [ɑ:].
What is the use of stress?
At word level (often called word stress), it is used in order to distinguish between parts of speech: thus “import” as a noun is stressed differently [ˈɪmpɔrt] than as a verb [ɪmˈpɔrt].
It is interesting to note that some languages have uniform, or fixed, word stress patterns across the board. For instance, in Polish the stress in multi-syllabic words falls on the penultimate syllable. Similarly, in Finnish it is the first syllable that receives primary stress in a word with multiple syllables (see this link for details). However, in many other languages, stress patterns vary from one word, or group of words, to another: English is one notorious case in this respect, making it harder for the adult learner to predict and correctly apply word stress.
At sentence level (often termed sentence stress), it allows for:
a) distinction between content words (nouns, verbs, adjectives, and adverbs) and function words (prepositions, pronouns, etc):
“John saw the house from a distance.” (the words in boldface are content words and receive stress)
“John saw the house from a distance.” (the words in boldface are content words and receive stress)
b) contrastive emphasis: “My brother has blue (and not brown or green) eyes.”
2. Intonation
Intonation is also the result of variation (rise and fall) in the pitch of the voice but is applied to phrases and sentences. Intonation is, in fact, a function of the interplay between stressed and unstressed syllables in an utterance (think of it like a wave through a stadium).
Intonation has a number of patterns and functions. Most notably, intonation is used for contrastive emphasis. For example, in English in the case of statements, the voice pitch gradually drops as it nears the end of the sentence (falling intonation) while in yes/no questions there is a rise in the pitch of the voice (rising intonation) toward the end of the utterance. To the listener, these are useful clues that help figure out if the speaker is making a statement or asking a question.
See examples of common intonation patterns in English here
Intonation can rise a few times within the same phrase or sentence. This is especially true when enumerating items on a list of choices (where rising intonation is an indication of more items coming):
Example of multiple rising patterns in the same phrase/sentence
3. Tone
Like intonation, tone is a matter of changes in pitch. Pitch variations can happen at word level (Ladefoged & Johnson 2011). The most famously cited case is that of the word “ma” [mɑ:] in Mandarin Chinese:
See this link for various tones for [mɑ:] in Mandarin
In some languages, differences in tone are indicative of grammatical distinctions. For example, in Edo, a language spoken in the Edo state in midwestern Nigeria, tone is used to indicate differences in the tense system of the language (Ladefoged & Johnson 2011, p.256). Thus, in Edo, a low tone on a monosyllabic transitive verb indicates present tense, while a high tone on the same verb means past tense.
In the next and final post on articulatory phonetics, we will be discussing articulatory processes including co-articulation and other features of connected speech.
References
Ladefoged, P. & K. Johnson (2011). A Course in Phonetics (6th ed.). Boston: Wadsworth, Cengage Learning.
Levis, J. (2018). Intelligibility, Oral Communication, and the Teaching of Pronunciation. Cambridge: Cambridge University Press.
Seikel, J. A., D. W. King, D. G. Drumright (2010). Anatomy & Physiology for Speech, Language & Hearing (4th ed.). NY: Cengage Learning.
