English Intelligibility: Sounds versus Rhythm?

By Jennie Parker

"How often we have had the experience of hearing [a nonnative speaker] speak English with perfectly intelligible consonants and vowels and with standard grammatical forms; and yet we have had the greatest of difficulty in understanding because the intonational patterns were entirely unnatural and strange to us." (Learning a foreign language (Nida, 1957))

​So, just how important are rhythm and intonational patterns to the intelligibility of English? In today’s literature on the subject, linguists are divided. Some claim that suprasegmental elements of speech (that is, features of speech that extend beyond individual sounds, such as word stress, rhythm, and intonation) are more important than the correct articulation of consonants and vowels. Others, however, claim that segmentals – these consonant and vowel sounds - are most important.  A third, more holistic perspective, and one that I embrace, is emerging. It suggests that the debate between suprasegmentals and segmentals is perpetuating a false dichotomy; the interaction between the two affects intelligibility, and they cannot always be separated.

​The first perspective points to studies that suggest that suprasegmentals, or prosody, play the most vital role in the overall intelligibility of speech. For example, English rhythm and intonation patterns provide information about what is important to a speaker’s message. Use of correct rhythm and intonation patterns is correlated with better intelligibility, higher proficiency ratings by native speakers, and better listener comprehension and recall. In contrast, nonnative rhythm and intonation patterns, including misplaced focus or stressing all words in an utterance equally, may elicit negative evaluations of the speaker and make sentence processing more difficult for the listener.

In contrast, other studies suggest that the correct articulation of phonemes has a larger impact on intelligibility than suprasegmentals. This may be especially true with regard to interactions between nonnative speakers of English. Because there are more nonnative speakers of English in the world than native speakers, some argue that more studies should assess the intelligibility of the speech of nonnative speakers speaking to other nonnative speakers (most studies involve nonnative speakers speaking to native speakers). Some studies suggest that when nonnative speakers employ correct elements of prosody, nonnative listeners actually have a more difficult time understanding what is said.

I tend to agree with a third, emerging perspective, however. In my experience, the interaction between segmental and suprasegmental elements of speech affect intelligibility, and sometimes, the two cannot be separated. For example, for native speakers of Mandarin and Japanese, a common communication problem in English is the insertion of a vowel sound between consonants in consonant clusters or after consonant clusters. So, while the vowel insertion is of a segmental nature, it involves syllables and word stress, as well. Thus, it is important for pronunciation instruction to address both segmental and suprasegmental elements. Furthermore, because language transfer issues differ depending on a learner’s first language, it is imperative for language educators to be able to shift instruction to address elements of speech that are most significantly impacting intelligibility for individual learners.

So what does all of this mean for the English language learner? It's important to address both segmentals (i.e., consonant and vowel production), as well as suprasegmentals (including word stress, rhythm, and intonation) in your English language instruction. An effective language instructor will research or have experience with common transfer issues from your first language and be able to assess your own speech for what is interfering most significantly with intelligibility. He or she will then help you to address those issues first in controlled language exercises and then in spontaneous speech.

Sources
"Suprasegmentals: An Overview" (Grant, 2018)
"Primary Stress and Intelligibility: Research to Motivate the Teaching of Suprasegmentals" (Hahn, 2004)
​"Segmental vs. Suprasegmental: Which is more important to teach?" (Wang, 2020) 

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