Applying Phonetics. Murray J. Munro

Verify this by producing a /t/ in isolation, taking care not to produce a vowel afterward. If you then try to do the same for /d/, you will probably find that you can't avoid producing a very short (voiced) vowel after you release the stop. In fact, English speakers do not generally produce voicing during the closure phase of a voiced plosive. Instead, the difference between English voiced and voiceless plosives is usually signaled by the time gap before the vowel that follows, which is very short in the case of /d/ and longer for /t/. Finally, notice that all approximants in English are voiced.

      TRY THIS

      ☛ Cut a rectangle of thin paper (20 × 5 cm) and hold it about 3–5 cm in front of your lips. Now say the word pair pay–bay slowly. You'll find that the /p/ of pay causes the paper to move much more than does the /b/ in bay. The difference is in the sequence of events that occurs for each consonant. For /p/, the plosive release and the vowel are separated by a puff of air called aspiration. As a result, the vowel doesn't actually start until some time after the release. For /b/, there is little or no puff of air; the vowel begins immediately after the release. This timing difference underlies the voiceless–voiced distinctions for /p/–/b/, /t/–/d/, and /k/–/g/ when they are produced at the beginning of a word.

      4.1.4 putting it all together for consonants

      Now that we've covered all the essential descriptive terminology for consonants, we can present a formulaic way of referring to them: voicing + place + manner. For instance, /b/ can be described as a voiced bilabial plosive, /θ/ as a voiceless dental fricative, and /tʃ/ as a voiceless palato‐alveolar affricate. For a chart of the full set of English consonants along with example words, see the Appendix.

4.2 vowels

      Unlike consonants, vowel sounds are created without an appreciable obstruction of the airflow. Instead of blocking the air, the speaker phonates while positioning the tongue and configuring the lips in a variety of non‐obstructive ways. These articulatory gestures change the RESONANCE properties of the vocal tract. Since all English vowels are voiced, vowel articulation modifies the acoustic shape of the laryngeal buzz. If you sustain voicing continuously while moving your tongue into different vowel configurations, you will get a sense of how resonance changes. It's worth noting here that English vowels fall into two broad categories: 1) monophthongs, in which one basic tongue position is the target, like the /i/ of see, and 2) diphthongs, which entail tongue movement from one distinct tongue position to another, like the /aʊ/ of cow.

We can't capture the differences among vowels in terms of manner of articulation because they are all produced in essentially the same manner: they are all relatively “open” sounds. Also, as already mentioned, they are all voiced in English. However, vowels do differ in place of articulation in the sense that their approximate tongue locations vary both vertically and horizontally. They also differ in a dimension known as tenseness and in the way the lips are shaped. Our list of descriptors for English vowels is summarized in Table 4.3.

Table 4.3 Descriptors for English Vowels

Dimension	Meaning	Possible Values
Height	Vertical location of the highest point of the tongue	High, mid, or low
Advancement	Horizontal location of the highest point of the tongue	Front, central, or back
Tension	Whether or not the vowel is said to entail muscular tension	Tense or lax
Lip configuration	Degree to which the lips are spread as opposed to shaped like an “o”	Unrounded or rounded

Figure 4.2 Tongue positions for front (left) and back (right) vowels (derived from x-ray images)

      (Source: Adapted from https://commons.wikimedia.org/wiki/File:Cardinal_vowel_tongue_position‐front.png and https://commons.wikimedia.org/wiki/File:Cardinal_vowel_tongue_position‐back.png)

      4.2.1 height and advancement

We describe both monophthongs and diphthongs in terms of how high and how far back the highest point of the tongue is. Figure 4.2 illustrates basic positions for several monophthongs, based on x‐ray tracings. On the left are front vowels, produced with the high point of the tongue more forward than for the back vowels, shown on the right. In each diagram, you can also see how the tongue height—closer to or farther from the roof of the mouth—varies. At one extreme is the high vowel /i/ as in bee, while at the other is the low vowel /ɑ/ as in saw (for most speakers).

      4.2.2 tension

Vowels are further classified as either tense or lax. These terms are a bit misleading in what they imply about vowel articulation. Though it has been suggested that tense vowels like the /i/ of beat seem to entail more overall muscular tension than lax vowels like the /ɪ/ of bit, this has not been supported by instrumental measurements. The labels have nonetheless “stuck” because they capture other differences. Tense and lax vowels do differ to some degree in duration, with lax vowels often being shorter. Also, tense vowels tend to be produced as more peripheral, in that the high point of the tongue is farther from the center of the mouth than for lax vowels.

      4.2.3 lip configuration

      The only vowel characteristic in Table 4.3 that can readily be seen in a mirror is lip configuration, which refers to whether the lips take on an “o”‐like, ROUNDED shape or a more spread, unrounded appearance. Only a handful of vowels in English, all of them back vowels, are rounded. These include the /u/ in boot and the /ʊ/ in book. Notice that these two vowels happen to be spelled the same way in these words.

      4.2.4 the monophthong inventory of english

Table 4.4 gives the IPA symbols and keywords for 10 monophthongs used in North American English dialects. Notice, however, that many speakers in the United States and nearly all speakers in Canada use only nine of these. Speakers with the smaller inventory do not make a distinction between word pairs like cot–caught because their dialect does not have a monophthong /ɔ/ (called open‐o) in such words as caught, taught, and bought.

      4.2.5 rhotic vowels

An important difference among English dialects around the world concerns the use of RHOTIC vowels. These are often referred to as r‐colored vowels, because their