On the status of final consonant clusters in english syllables

JOURNAL OF VERBALLEARNINGAND VERBALBEHAVIOR23, 343-356 (1984)

On the Status of Final Consonant Clusters in English Syllables REBECCA TREIMAN

Indiana University Linguistic and behavioral evidence suggests that the syllable is composed of two major constituents, an onset and a rime. The onset is the initial consonant or consonant cluster. The rime is the remainder of the syllable, excepting any inflectional endings or appendices. The internal structure of the rime was studied in four experiments. When an obstruent followed the vowel, subjects most readily divided the rime between the vowel and the obstruent. Thus, final consonant clusters beginning with obstruents formed cohesive units. Postvocalic liquids were grouped with the vowel rather than the final consonant. Postvocalic nasals were intermediate. These results are consistent with linguistic notions of a sonority hierarchy, by which classes of consonants differ in their affinity with vowels.

Syllables and phonemes play important roles in the processing of speech. Also important, according to recent research, may be units intermediate in size between syllables and phonemes. Theories of syllable structure (e.g., Cairns & Feinstein, 1982; Fudge, 1969; Halle & Vergnaud, 1980; MacKay, 1972; Vergnaud & Halle, 1979) postulate that the syllable is not simply a string of phonemes. Rather, the syllable possesses a hierarchical internal structure. The major constituents of the English syllable, in the terminology of Halle and Vergnaud (1980), are the onset and the rime. The onset, which is optional, is the initial consonant or consonant cluster. The rime is the remainder of the syllable, with the exception of any inflectional endings. Inflectional endings, or appendices, occur only after morpheme boundaries. They will be discussed further below. The rime itself is composed of a peak and a coda. The peak, This research was supported by National Science F o u n d a t i o n Grant BNS 81-09892. I t h a n k Shellie Haut-Rogers, Erica Motley, and Ann Farrell for their assistance. Arthur Abramson, Jola Jakimik, Joe Stemberger, and Linda Smith offered helpful comments on an earlier draft of the manuscript, as did an anonymous reviewer. Some of the results were presented at the meeting of the Psychonomic Society, Minneapolis, November 1982. Requests for reprints should be sent to the author at Department of Psychology, Indiana University, Bloomington, Ind. 47405.

which is obligatory, is the vowel nucleus of the syllable. The coda, which is optional, is the following consonant or consonant cluster. For example, the word "grasp" has the onset/gr/and the rime/~esp/. The peak is/~e/and the coda is/sp/. (See the bottom of Table 1 for a key to the notation used in this paper.) Both linguistic and behavioral evidence support the view that onsets and rimes are cohesive units. Much of the linguistic evidence is distributional. In English, virtually any onset can occur with virtually any rime (e.g., Fudge, 1969). That is, the two units are almost independent. In contrast, severe restrictions govern the c o o c c u r e n c e of peaks and codas within the rime. For example, the vowel/i/cannot occur before a syllable-final /sp/ cluster. Stress phenomena provide a further reason to distinguish between onset and rime. In English, the rules of stress assignment refer to the rime, and the onset is completely irrelevant (Chomsky & Halle, 1968). Behavioral evidence for the onset/rime distinction comes from several sources. One source of evidence is errors in the spontaneous production of speech. MacKay (1972) analyzed errors made by German and English speakers in which two words with similar meanings were inadvertently blended. An English example 343 0022-5371/84 $3.00 Copyright© 1984by AcademicPress, Inc. All fightsof reproductionin any formreserved.

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would be the combination of "grasp" and "clutch" to produce the nonword " g r u t c h . " M a c K a y (1972) reported that when breaks occurred within a syllable, consonant clusters remained intact more often than would be expected by chance. Breaks were more likely to occur before the vowel than after it. These patterns, which are exemplified by the blend " g r u t c h , " support the view that the syllable is composed of an onset and a rime unit. Further evidence that onsets and rimes function as cohesive units in the processing of speech comes from studies in which subjects were taught to manipulate nonsense syllables in various ways. For example, Treiman (1983, Experiment 7) taught subjects a word game in which the onset of one syllable was blended with the rime of another. An example would be the combination of /flirz/ and /gruns/ to produce /fluns/. Also taught were games in which the onsets or rimes were divided, as when /flirz/and/gruns/combined to yield/fruns/, /flins/, or/flirs/. The results showed that the game that kept the onset and rime intact was learned with fewer errors than the other three games. Further, when other subjects were asked to blend the syllables in any way they chose, they most often joined the onset of the first syllable with the rime of the second. Finally, there is evidence that onsets function as cohesive units in tasks involving the perception and identification of speech sounds. Treiman, Salasoo, Slowiaczek, and Pisoni (1982), examining the influence of syllable structure on adults' phoneme monitoring performance, found that subjects took longer to detect syllableinitial consonants when the consonants were part of a cluster (as in/sna/) than when they were singletons (as in /sa/ or /san/). Similar results have been obtained with 5year-old children in a study using error rate rather than response time as the dependent variable (Treiman, 1980). Children more often failed to d e t e c t / s / w h e n it occurred in /sna/ than when it occurred in /sa/ or

/san/. In conclusion, there is evidence that onsets and rimes are involved in speech production, speech perception, and metalinguistic tasks such as the learning of word games. Although behavioral evidence supports the view that syllables are divided into onset and rime units, the behavioral evidence with respect to the postulated division of rimes into peak and coda is less clear. MacKay's (1972) analyses of the fate of consonant clusters in speech errors did not differentiate between final consonant clusters (codas) and initial consonant clusters (onsets). Consequently, it was not clear whether final consonant clusters remained intact more often than expected by chance. In a study of word games, Treiman (1983) found strong evidence for an onset/ rime division but did not find clear support for a peak/coda division. A rule that kept the peak and coda intact (e.g., /flirz/ + /gruns/---~/flins/) was n o t learned more easily than a rule that divided these units (e.g., /flirz/ + / g r u n s / ~ /flirs/). Also, subjects who were allowed to combine syllables in any way they chose did not prefer blends of the former type to blends of the latter type. The present experiments further investigated the internal structure of the rime. This was done by testing two possible explanations for Treiman's (1983) failure to find evidence consistent with the postulated peak/coda division in tasks of the kind described above. The first possibility is that subjects treated certain of the nonsense syllable stimuli as if they had inflectional endings or appendices. For example, subjects could have c o n s i d e r e d / f l i r z / a s the base syllable/flir/plus the ending/z/. The/z/corresponds to the plural, possessive, or third person singular present morpheme. If subjects preferred to break syllables such as /flirz/at the rime/appendix boundary, breaks at that boundary would be preferred to breaks within the rime. That is, breaks between the final consonants would outnumber breaks after the vowel. The hy-

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pothesis that subjects preferentially divide syllables at the rime/appendix boundary predicts differences among syllables depending on whether their final consonants must be, may be, or may not be considered appendices./flibz/is a syllable in which the final consonant must be considered an appendix. Uninflected English syllables never end in /bz/. The tendency to divide final consonant clusters may be strongest for syllables of this kind. /flirz/is an example of a syllable in which the final consonant may be considered an appendix. The /z/ could also be considered part of the rime, /rz/ being a legal English coda (as in "Mars"). Subjects' tendency to divide the final consonant cluster may depend on whether they consider the /z/ as an appendix or as part of the rime. Finally, /gruns/is an example of a syllable in which the final consonant cannot be considered an appendix. The correct form of the inflectional ending in this case would be/z/rather than/s/. According to the hypothesis under consideration, the final consonant cluster should be treated as a unit with syllables of this kind. The stimuli in Treiman's (1983) experiments included a number of syllables in which the final consonants could be considered appendices. Thus, one reason for the failure to find evidence for a peak/coda division within the rime may have been that subjects treated the syllables as having appendices and divided them at the rime/appendix boundary. A second reason why Treiman (1983) may have failed to find clear evidence for a peak/coda division is that many of the syllables used in the experiments had liquids (i.e., /1/and/r/) after the vowel. MacKay (1978) and Stemberger (1983) have recently suggested, based on speech error data, that postvocalic liquids are more closely associated with the vowel than are other postvocalic consonants. Thus, the/r/ in/flirz/may be part of the peak rather than part of the coda. According to this hypothesis, breaks between the final consonants would be favored when a liquid follows the

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vowel. Final consonant clusters should function as cohesive units only when they begin with nonliquid consonants. EXPERIMENT 1 Experiment 1 used a version of the blending task previously developed by Treiman (1983). The stimuli were vowe l - c o n s o n a n t - c o n s o n a n t (VCC) syllables such /esp/ and /~e-qk/. Subjects were asked to combine the two stimulus syllables into one new syllable by taking part of the first syllable followed by part of the second syllable. Two different combinations may be expected. The V/CC blend breaks each syllable after the first C, yielding/~sk/. Treiman (1983) reported that subjects showed no significant preference for one type of blend over the other. However, the nature of the final consonant (obligatory appendix or not) and the nature of the postvocalic consonant (liquid or nonliquid) were not controlled in the earlier study. Experiment 1 tests whether these factors affect subjects' preferred blends. The first hypothesis discussed above predicts that subjects will make more V/CC blends when the final consonant cannot be an appendix than when it can be or must be an appendix. The second hypothesis predicts that subjects will make more V/CC blends when the second consonant is not a liquid than when it is a liquid.

Method Subjects. Sixteen subjects participated. They were chosen from a pool of students enrolled in summer courses at Indiana University and were paid for their participation. All subjects in this and subsequent experiments were native speakers of English. Stimuli, The stimuli for Experiment I were 26 pairs of VCC syllables. Samples are shown in Table 1. Eighteen pairs had postvocalic nonliquid consonants. The nonliquids included nasals (e.g., /n/, /~q/), fricatives (e.g., /f/, /s/), and stops (e.g., /p/, /b/). The final consonants of six of these pairs could not be considered appendices, either because they were not possible forms

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REBECCA TREIMAN TABLE 1 SAMPLE STIMULI AND RESULTS FOR EXPERIMENT 1 Mean no. of responses

Postvocalic nonliquids Final C must not be appendix Final C might be appendix Final C must be appendix

Example

V/CC

VC/C

asp + ~eqk

2.50 (1.71) 3.69 (lr82) 3.25 (1.65) 9.44 (4.07)

2.25 (1.61) (1.35) 2.06 (1.81) 6.00 (3.92)

(1.24) .63 (.72) .69 (.95) 2.56 (2.22)

1.31 (1.25) 1.63 (1.41) 2.94 (2.46)

1.88 (1.54) 1.38 (1.50) 3.25 (2.65)

.81 (1.28) 1.00 (.89) 1.81 (1.87)

aft -b lps obd + aevz

All postvocalic nonliquids Postvocalic liquids Final C must not be appendix

als + ort

Final C might be appendix

arz + A l d

All postvocalic liquids

1.69

Other 1.25

Note. Standard deviations are in parentheses. Key to phonetic notation:

i 1 e ae

beet bit bet bat

u o n a

boot bought but cot

0 5 1] j

thin then thing j_'oe

of any inflectional ending (as with/asp/and /~e~k/) or, in other cases, because they were not correct forms of these endings given the preceding consonants. In six other cases the final consonants could be considered either appendices or parts of the rime, and in the remaining six cases the final consonants had to be appendices. Eight other stimulus pairs had postvocalic liquids. For four of these pairs the final consonants could not be appendices, and for the other four the final consonants could either be appendices or parts of the rime. (There is only one case involving a postvocalic liquid in which the final consonant must be an appendix, /lz/, so pairs of this kind were not included.) All stimulus syllables were phonologically legal syllables of English, conforming to the template given by Vergnaud and Halle (1979). Also, both the V/CC and VC/C blends were phonologically legal. A large majority of the stimuli and possible responses were nonwords. To control for

any possible lexical effects, the V/CC and VC/C blending rules yielded equal numbers of real word responses. Procedure. Subjects were told that they would hear two nonsense syllables on every trial. They were to combine the two syllables into one new syllable by taking part of the first syllable followed by part of the second syllable. Their answer should b e one syllable long. Subjects were informed that there was no one right answer and that they could choose to combine different pairs of syllables in different ways. On each trial, the experimenter said each syllable separately and the subject repeated it. The experimenter then said the two syllables as a pair and the subject repeated them both twice. If the subject misrepeated the syllables the experimenter corrected the subject. The subject then gave his or her answer. If the subject's answer did not conform to the instructions (e.g., if it was two syllables long), the experimenter repeated

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the relevant part of the instructions and asked the subject to give another answer. Otherwise, the experimenter did not provide feedback to the subject on his or her response. The order of stimulus pairs was randomly chosen for each subject. Results and Discussion Responses were classified as V/CC blends, VC/C blends, or " o t h e r . " Some of the " o t h e r " responses combined the VC of the first stimulus with the CC of the second or the V of the first stimulus with the final C of the second (e.g.,/arz/ + /Ald/-->/arld/ o r / a d / ) . Others included phonemes that were not in the stimulus syllables or that were misordered (e.g.,/arz/ + /Ald/-->/ars/ or/rald/). Table 1 shows the mean numbers of each type of response for the various stimulus categories. For stimuli with postvocalic nonliquid consonants, the proportion of V/CC blends relative to all non" o t h e r " responses was no higher when the final consonant could not be an appendix than when it could be or had to be an appendix. An analysis of variance by subjects failed to find a significant difference among these three categories, F(2,30) = 2.50, p > .09; an analysis by stimuli also yielded nonsignificant results, F(2,15) = 1.I0. Thus, the results were pooled across all stimuli with postvocalic nonliquids. For these stimuli, the number of V/CC blends significantly exceeded the number of VC/C blends. This result held whether statistical tests were done across subjects, t(15) = 1.79, p < .05, one tailed, or across stimuli, t(17) = 2.97, p < .005, one tailed. That is, subjects preferred to treat final consonant clusters beginning with nonliquids as units. For stimuli with postvocalic liquids, the status of the final consonant again failed to have the postulated effect. The proportion of V/CC blends relative to all non-"other" responses was no higher when the final consonant could not be an appendix than when it could be an appendix. Indeed, there was a trend in the reverse direction, across

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subjects t(15) = 1.82, across stimuli t(6) = 2.06. When the results for all stimuli with postvocalic liquids were pooled, V/CC and VC/C blends did not differ significantly, across subjects t(15) = .26, across stimuli t(7) = .63. A comparison of subjects' responses to stimuli with postvocalic nonliquids and stimuli with postvocalic liquids revealed that the proportion of V/CC blends relative to all non-"other" responses was reliably higher for stimuli with postvocalic nonliquids than for stimuli with postvocalic liquids, across subjects t(15) = 1.84, p < .05, onetailed, across stimuli t(24) = 2.18, p < .025, one tailed. The proportion of V/CC blends relative to all n o n - " o t h e r " responses was .61 for stimuli with postvocalic nonliquids and .47 for stimuli with postvocalic liquids. Thus, the nature of the postvocalic consonant affected subjects' responses. Also, the proportion of " o t h e r " responses tended to be higher for stimuli with postvocalic liquids (.23) than for stimuli with postvocalic nonliquids (. 14), across subjects t(15) = 1.38, across stimuli t(24) = 1.60, p < .1 for both, one tailed. " O t h e r " responses that combined the VC of the first stimulus with the CC of the second were more often phonologically legal for the stimuli with postvocalic liquids than for the other stimuli, and this may have produced the apparent difference between the two categories of stimuli. In summary, the results of Experiment 1 support the view that postvocalic liquids and nonliquids function differently. Nonliquids were grouped more closely with the final consonant than with the vowel nucleus. Thus, V/CC blends predominated for these stimuli. In contrast, liquids were grouped as often with the vowel as with the final consonant. Although VC/C blends did not significantly outnumber V/CC blends for stimuli with postvocalic liquids, as might be expected if liquids were part of the peak (MacKay, 1978; Stemberger, 1983), liquids did appear to be more closely linked with the vowel than were

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other postvocalic consonants. The present findings do not support the hypothesis that subjects treat syllable-final/s/,/z/,/t/, and /d/ as appendices when possible and that they prefer to divide syllables at the rime/ appendix boundary. VC/C blends were no more frequent when the final consonant could be considered an appendix than when it could not. The results of Experiment 1 imply that Treiman (1983) failed to find a preponderance of blends that broke rimes between the vowel and the final consonant cluster because her stimulus syllables included those with postvocalic liquids as well as those with other postvocalic consonants. When syllables with postvocalic liquids are excluded, subjects do apparently prefer to treat final consonant clusters as units. EXPERIMENT 2

The results of Experiment 1 are consistent with the view that postvocalic liquids are linked more closely with the vowel nucleus than are other postvocalic consonants. These results may be viewed in terms of a sonority hierarchy that has been proposed by several linguists (e.g., Hooper, 1976; Kiparsky, 1979; Jespersen, as reported in Malmberg, 1963; Vennemann, 1972). In this view, segments are grouped in a syllable based on their sonority. Although the exact ordering differs in different accounts of the sonority hypothesis, it is generally agreed that vowels are most sonorous. They are followed in decreasing order by glides (which include/w/and/y/), liquids, nasals, and obstruents (which include stops and fricatives), a Phonetically, the hierarchy can be viewed in terms of degree of opening or audibility (Malmberg, 1963). The airstream is maximally ob-

1 Affricates are also classed as obstruents, but they are not included as postvocalic consonants in these experiments since they are relatively infrequent and since Hooper (1976) states that their position in the sonority hierarchy is not clear.

structed in the case of obstruents. In the production of nasals, the oral cavity is closed but the air can flOW out through the nose. Liquids show little or no oral closure, and glides and vowels are the most open sounds. Distributional evidence supports the proposed sonority hierarchy. Obstruents tend to be farthest from the vowel. They generally occupy the initial positions of syllable-initial clusters and the final positions of syllable-final clusters. Nasals are closer to the vowel than obstruents. For example, the sequence/sn/is legal in syllableinitial position in English. The reverse sequence,/ns/, is illegal. In syllable-final position, /ns/is legal b u t / s n / i s not. Liquids are closer to the vowel than nasals, as shown by the fact that/rm/can occur after a vowel while /mr/cannot. Finally, glides are located adjacent to vowels, and postvocalic glides are generally considered part of the vowel nucleus (e.g., MacKay, 1978). The finding of Experiment 1 that postvocalic liquids are grouped more closely with the vowel nucleus than are other postvocalic consonants is consistent with one portion of the proposed sonority hierarchy. However, the postvocalic nonliquids of Experiment 1 included stops, fricatives, and nasals, and it was not possible to test whether nasals were grouped more closely with the vowel than were other consonants, as the sonority hierarchy hypothesis predicts. Therefore, Experiment 2 compared three classes of postvocalic consonants-obstruents, nasals, and liquids. If these classes have increasing affinity with vowels, the proportion of V/CC blends should be highest for stimuli with postvocalic obstruents, intermediate for stimuli with postvocalic nasals, and lowest for stimuli with postvocalic liquids. Secondarily, Experiment 2 again asked whether the status of the final consonant--whether it must, might, or might not be an inflectional ending--affected subjects' responses. This variable was found not to have an effect in Experiment 1, and a similar result was expected in Experiment 2.

349

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Method

Results and Discussion

Subjects. Twenty-four subjects, chosen from the same pool as the subjects in Experiment 1, took part. None had participated in the earlier experiment. Stimuli. The stimuli for Experiment 2 were 36 pairs of VCC syllables. Samples are shown in Table 2. Twelve pairs had the postvocalic obstruents/b/, /g/, /p/, and/t/; twelve had the postvocalic nasals /m/, /n/, and/-q/; and twelve had the postvocalic liquids/1/and/r/. As shown in the table, the stimuli in each category were evenly divided into two groups which differed in the status of the final consonant. All stimuli and V/CC and VC/C responses were phonologically legal in English. A small number of responses, evenly divided between the V/CC and VC/C categories, were real words. Procedure. The procedure was identical to that of Experiment 1.

Table 2 shows the mean numbers of V/ CC, VC/C, and "other" responses for each stimulus type. For stimuli with postvocalic obstruents, the proportion of V/CC responses relative to all non-"other" responses was no higher when the final consonant could not or might not be an appendix than when it had to be an appendix, across subjects t(23) = - 1 . 1 7 , across stimuli t(10) = - . 3 5 . Therefore, the results were pooled for all stimuli with postvocalic obstruents. The number of V/CC blends significantly exceeded the number of VC/C blends for these stimuli, across subjects t(23) = 3.08, p < .005, one tailed, across stimuli t(11) = 3.77, p < .0025, one tailed. For stimuli with postvocalic nasals, the proportion of V/CC responses relative to all non-"other" responses was again no higher when the final consonant could not be an appendix than when it had to be an ap-

TABLE 2 SAMPLE STIMULI AND RESULTS FOR EXPERIMENT 2 Mean no. of responses

Postvocalic obstruents Final C must not or might be appendix Final C must be appendix

Example

V/CC

VC/C

Other

uts + ep0

3.21 (1.64) 3.58 (1.79) 6.79 (3.08)

1.71 (1.20) 1.58 (1.69) 3.29 (2.63)

1.08 (1.06) .83 (.92) 1.92 (1J35)

2.54 (1.69) 3.08 (1.41) 5.63 (2.55)

2.83 (1.61) 2.25 (1.26) 5.08 (2.19)

.63 (1.24) .67 (.82) 1.29 (1.63)

2.00 (1.74) 1.92 (1.79) 3.92 (3.40)

2.13 (1.57) 2.00 (1.72) 4.13 (3.01)

1.88 (.99) 2.08 (1.591 3.96 (2.22)

Abd + ugz

All postvocalic obstruents Postvocalic nasals Final C must not be appendix Final C must be appendix

arlk + mO amd + ll]Z

All postvocalic nasals Postvocalic liquids Final C must not be appendix Final C might or must be appendix All postvocalic liquids

ols + ar0

orz + aid

Note. Standard deviations are in parentheses.

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REBECCA TREIMAN

pendix, across subjects t(23) = - 1 . 6 4 , across stimuli t(10) = - 1 . 0 6 . For the stimuli with postvocalic nasals, the numbers of V/CC and VC/C responses were statistically indistinguishable, across subjects t(23) = .59, across stimuli t(11) = .49. For stimuli with postvocalic liquids, the status of the final consonant also had no effect. The proportion of V/CC responses relative to all non-"other" responses was no higher when the final consonant could not be an appendix than when it could be one, across subjects t(23) = - . 2 8 , across stimuli t(10) = . 12. For these stimuli, VC/ C responses did not significantly outnumber V/CC responses, across subjects t(23) = . 17, across stimuli t(11) = .31. Analyses of variance on the proportions of V/CC responses relative to all non" o t h e r " responses revealed a significant difference among the three categories of stimuli, across subjects F(2,46) = 5.82, p < .006, across stimuli F(2,33) = 3.87, p < .05. The proportion of V/CC responses relative to non-"other" responses was .67 for the obstruent category, .53 for the nasal category, and .49 for the liquid category. This ordering is predicted by the hypothesis that obstruents, nasals, and liquids have increasing affinity with vowels. Tukey's tests, p < .05, showed that the difference between the obstruent and liquid categories was significant, both for the analysis by subjects and for the analysis by stimuli. The difference between obstruents and nasals was significant by the same test in the subjects analysis, but did not reach the .05 level in the stimulus analysis. Nasals and liquids did not differ significantly. Analyses of variance on the numbers of " o t h e r " responses showed that these responses varied with stimulus category, across subjects F(2,46) = 20.65, across stimuli F(2,33) = 13.66, p < .0001 for both. There was a higher proportion of " o t h e r " responses to stimuli with postvocalic liquids (.33) than to stimuli with postvocalic obstruents (.16) or nasals (.11), Tukey's, p < .01. As in Experiment 1, the difference

among stimulus categories probably arose because " o t h e r " responses that combined the VC of the first stimulus with the CC of the second were more often phonologically legal for stimuli with postvocalic liquids than for stimuli with postvocalic obstruents or nasals. In summary, the results of Experiment 2, like those of Experiment 1, fail to support the hypothesis that subjects preferentially treat syllable-final/s/,/z/,/t/, a n d / d / a s appendices and that they divide syllables between the end of the rime and the appendix. The results of Experiment 2 do support the hypothesis that subjects treat different classes of postvocalic consonants differently. Only for stimuli with postvocalic obstruents did V/CC blends significantly exceed VC/C blends. For stimuli with postvocalic nasals and stimuli with postvocalic liquids, subjects showed no reliable preferences. EXPERIMENT 3 The differences found in Experiment 2 among stimuli with postvocalic obstruents, nasals, and liquids were relatively small. The difference between nasals and liquids, although in the direction predicted by the sonority hierarchy hypothesis, was not significant. The smallness of the differences may have resulted from the use of a withinsubjects design. Subjects may have picked a particular blending rule and used it for a number of successively presented stimuli. To alleviate possible problems associated with a within-subjects design, Experiment 3 used a between-subjects design. One group of subjects received stimuli with postvocalic obstruents, a second group received stimuli with postvocalic nasals, and a third group received stimuli with postvocalic liquids. Of particular interest in Experiment 3 was the performance of the postvocalic liquid group. Neither Experiment 1 nor Experiment 2 found a significant preference for VC/C responses over V/CC responses for stimuli with postvocalic liquids. Such a preference is predicted by the hy-

351

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pothesis that postvocalic liquids are part of the peak (Mackay, 1978; Stemberger, 1983). However, the postvocalic liquid stimuli in Experiments 1 and 2 were interspersed with other s t i m u l i - - s t i m u l i for which V/CC blends were favored. Experiment 3 asked whether a preference for VC/ C responses emerged when stimuli with postvocalic liquids were presented separately.

TABLE 3 RESULTS OF EXPERIMENT 3 Mean no. of responses

Postvocalic obstruents Postvocalic nasals Postvocalic liquids

V/CC

VC/C

Other

11.65 (5.18) 8.50 (4.77) 4.15 (4.32)

4.00 (2.58) 7.65 (3.41) 9.80 (4.46)

4.35 (3.72) 3.85 (5.02) 6.05 (3.14)

Note. Standard deviations are in parentheses.

Method Subjects. Sixty Indiana University students participated to fulfill an introductory psychology course requirement. Twenty were assigned to each condition of postvocalic obstruent, postvocalic nasal, and postvocalic liquid. Stimuli. The stimuli for Experiment 3 were pairs of VCC syllables similar to those used in Experiment 2. There were 20 pairs in each condition. The stimuli in the postvocalic obstruent condition had/b/,/g/,/p/, /t/, /k/, /f/, /v/, /0/, and /~/ as postvocalic consonants. The stimuli in the postvocalic nasal condition had /m/, /n/, and/-q/after the vowel, and those in the postvocalic liquid condition had /1/ a n d / r / after the vowel. As in the earlier experiments, all stimuli and V/CC and VC/C responses were phonologically legal in English. A small number of responses, evenly divided between the V/CC and VC/C categories, were real words. Procedure. The procedure was identical to that of Experiments 1 and 2. Results and Discussion Table 3 shows the mean numbers of V/ CC, VC/C, and " o t h e r " responses for each condition. In the postvocalic obstruent condition, V/CC blends significantly exceeded VC/C blends across subjects t(19) = 4.69, across stimuli t(19) = 5.41, p < .0005 for both, one tailed. This result is similar to that found in Experiment 2. Also as in Experiment 2, V/CC and VC/C blends were statistically indistinguishable for stimuli with postvocalic nasals, across subjects

t(19) = .58, across stimuli t(19) = .73. The results of the postvocalic liquid condition differed somewhat from those of the earlier experiments. Here there was a reliable preference for VC/C responses over V/CC responses for stimuli with postvocalic liquids, across subjects t(19) = 3.08, p < .005, one tailed, across stimuli t(19) -= 5.26, p < .0005, one tailed. The proportion of V/CC responses relative to all non-"other" responses was .74 for the postvocalic obstruent condition, .53 for the postvocalic nasal condition, and .30 for the postvocalic liquid condition. Analyses of variance revealed that these values differed significantly, across subjects F(2,57) = 15.04, p < .0001, across stimuli F(2,57) = 32.16, p < .0001. Tukey's tests showed that the proportion of V/CC responses relative to non-"other" responses was significantly higher for obstruents than for nasals, and significantly higher for nasals than for liquids, both p's were <.05 in the subjects analysis and <.01 in the stimulus analysis. The proportion of " o t h e r " responses was .30 in the postvocalic liquid condition, .22 in the postvocalic obstruent condition, and .19 in the postvocalic nasal condition. These values did not differ significantly in an analysis of variance by subjects, F(2,57) = 1.63, but an analysis of variance by stimuli did yield significant results, F(2,57) = 6.76, p < .005. According to the latter analysis, there were more " o t h e r " responses to stimuli with postvocalic liquids than to stimuli with postvocalic obstruents, Tukey's, p < .05, or nasals, Tu-

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key's, p < .01. The trend is the same as in Experiment 2, but since the result did not generalize across subjects its robustness must be questioned. The results of Experiment 3 indicate that subjects treat postvocalic obstruents, nasals, and liquids differently. The differences are as predicted by the sonority hierarchy hypothesis. For postvocalic obstruents, as previously found in Experiment 2, V/CC blends were favored. This result is consistent with the view that postvocalic obstruents are part of the coda. For postvocalic nasals, again as in Experiment 2, V/ CC and VC/C blends were equally frequent. Postvocalic nasals, then, seem to occupy an intermediate position. Finally, postvocalic liquids appear to be part of the peak. When stimuli with postvocalic liquids were presented alone, subjects preferred to divide them between the liquid and the final consonant. The use of a between-subjects design, in which subjects received stimuli with only one type of postvocalic consonant, led to large differences among stimulus categories.

distinguishable. A possible reason for this outcome was that the postvocalic consonants were frequently liquids and nasals. According to the sonority hierarchy hypothesis, these phonemes are more closely allied with the vowel than are obstruents. Their inclusion may have made the VC/C game easier to learn than it otherwise would be. Experiment 4 directly tested the hypothesis that the ease of the V/CC game relative to the VC/C game varies for different classes of postvocalic consonants. Three groups of subjects were included. One group learned games of both types using stimuli with postvocalic obstruents, the second used stimuli with postvocalic nasals, and the third used stimuli with postvocalic liquids. The sonority hierarchy hypothesis predicts that the groups should differ in their performance on the V/CC game relative to the VC/C game. The obstruent group should find the V/CC game easier than the VC/C game, the liquid group should find the V/CC game more difficult than the VC/C game, and the nasal group should perform comparably on the two games.

EXPERIMENT 4 The fourth experiment sought to extend the results of the first three experiments by asking whether VCC syllables containing postvocalic obstruents, nasals, and liquids function differently in another type of word game. The task used here was one previously employed by Treiman (1983, Experiment 5b). Rather than examining which rule subjects prefer, as in the earlier experiments, this task compared each subject's ability to learn two word games. One game, the V/CC game, divided VCCs after the vowel. The second game, the VC/C game, divided the same VCCs between the two consonants. Treiman (1983) hypothesized that the V/CC game would be easier to learn than the VC/C game, since it respected the division between the peak and the coda. This prediction was not confirmed. Rather, the numbers of errors in learning the two games were statistically in-

Method Subjects. A total of 64 subjects participated. They were chosen from a pool of subjects enrolled in summer school and regular courses at Indiana University. Thirty-two subjects were assigned to the postvocalic obstruent group. Sixteen were assigned to each of the postvocalic nasal and postvocalic liquid groups. (The reason for the larger number of subjects in the postvocalic obstruent group is explained below.) Stimuli. The word games of Experiment 4 involved turning one syllable into two. Sample stinmli are shown in Table 4. Each V/CC game divided the stimulus syllable after the V, yielding as the first response syllable the V of the stimulus followed by a C that remained constant throughout the game. The second response syllable was a fixed V followed by the CC of the stimulus.

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FINAL CONSONANT CLUSTERS TABLE 4 SAMPLE STIMULI AND RESPONSES FOR EXPERIMENT 4

V/CC game Postvocalic obstruents Postvocalic nasals Postvocalic liquids

ISk ~ It + aepO~ aet+ enj --~ ez + lmf --0 lz + ars---, at + or0 ~ ot +

T h e c o r r e s p o n d i n g VC/C g a m e u s e d the same stimulus syllables and the same fixed V and C. The stimulus syllables, however, were divided differently. The first response syllable for the VC/C game was the VC of the stimulus followed by the fixed C. The second response syllable was the fixed V f o l l o w e d b y the final C o f the stimulus. Each game included one practice item and 14 test items. All stimuli and r e s p o n s e s were phonologically legal English syllables, and the V/CC and VC/C games produced equal numbers of real word responses. For the postvocalic nasal and the postvocalic liquid c o n d i t i o n s , two pairs o f games were constructed. The two pairs of games in e a c h c o n d i t i o n u s e d di!fferent stimulus syllables and different fixed Vs and Cs. This was done to help ensure that the results were not specific to particular phonemes. The VCC stimulus syllables in each pair of games included syllables with two or three different p o s t v o c a l i c c o n s o n a n t s : / m / , / n / , a n d / ~ i / f o r the nasal condition a n d / 1 / a n d / r / f o r the liquid condition. Half of the 16 subjects in each condition learned each pair of games. For the postvocalic obstruent condition, four pairs of games w e r e c o n s t r u c t e d . T h e l a r g e r n u m b e r of g a m e pairs was used b e c a u s e English contains more obstruents than liquids or nasals. E a c h game pair included VCC stimuli with three different p o s t v o calic o b s t r u e n t s - - r o u g h l y e q u a l to the number of different postvocalic consonants in the liquid and nasal conditions. Different sets of p o s t v o c a l i c o b s t r u e n t s along with different fixed Vs and Cs were used in the different game pairs in order to sample a variety of postvocalic obstruents. The ob-

Ask

ApO ~enj ~emf its ir0

VC/C game lsk ~ 1st + zepO~ ~ept+ enj ~ enz + lmf --0 lmz + ars--* art + or0 --~ ort +

Ak

AO ~ej ~ef is i0

struents used included/p/, /t/, /k/, /f/, and /s/. Eight subjects in the p o s t v o c a l i c obs t r u e n t c o n d i t i o n w e r e assigned to e a c h pair of games. Procedure. The subject was told that he or she would learn a game involving nonsense syllables. The experimenter read the practice item, indicating the stimulus syllable and the two response syllables into which it was transformed. The subject repeated the stimulus and response syllables. The experimenter then explained that the subject would be asked to transform new syllables following the p r o c e d u r e used in the example. Before presenting the first test syllable, the experimenter read the practice item again. For each test syllable, the subject first repeated the syllable after the experimenter. The e x p e r i m e n t e r c o r r e c t e d any misrepetition. The subject then gave his or her r e s p o n s e . If the s u b j e c t responded wrongly, the e x p e r i m e n t e r provided the correct response syllables. Also, if the subject failed to respond within 20 seconds the experimenter gave the correct answer. E a c h subject participated for two sessions. Half the subjects assigned to each game learned the V/CC game in session one and the VC/C game in session two. Half had the reverse order. The sessions were scheduled at least one week apart. Results and Discussion Table 5 shows the results in terms of several measures of performance. " N u m b e r of e r r o r s " refers to the total number of errors on the 14-item test. Each response syllable was s c o r e d s e p a r a t e l y , so the m a x i m u m possible number of errors was 28. " F i r s t

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REBECCA TREIMAN TABLE 5 RESULTS OF EXPERIMENT 4 No. of errors

Postvocalic obstruents Postvocalic nasals Postvocalic liquids

First correct trial

Longest run

V/CC game

VC/C game

V/CC game

VC/C game

V/CC game

VC/C game

3.91 (4.21) 3.57 (4.65) 8.06 (5.66)

5.47 (4.38) 3.06 (2.11) 3.50 (2.71 )

2.88 (1.98) 2.56 (2.34) 4.94 (3.89)

3.47 (2.82) 2.75 (2.14) 2.31 (1.78)

9.63 (3.82) 9.75 (4.37) 6.50 (3.90)

8.00 (4.18) 9.31 (2.85) 9.44 (2.87)

Note. Standard deviations are in parentheses.

correct trial" refers to the first test trial on which both r e s p o n s e syllables w e r e correct. " L o n g e s t r u n " is the longest string of test trials on which both response syllables were correct. Preliminary analyses showed that the games within each condition did not differ significantly, so the results reported below are pooled across the games. For the postvocalic obstruent group, the V/CC games led to reliably f e w e r errors than the VC/C games, t(31) = 1.80, p < .05, one tailed. The two types of games were statistically indistinguishable in the position of the first correct trial, t(31) = 1.00, but subjects made significantly longer runs with the V/CC games than with the VC/C games, t(31) = 2.01, p < .05, one tailed. Thus, two of the three p e r f o r m a n c e m e a s u r e s show that V/CC games were significantly easier than VC/C g a m e s w h e n p o s t v o c a l i c obstruents were used. For the postvocalic nasal group, the two types of games were statistically indistinguishable on all t h r e e p e r f o r m a n c e measures. Neither in n u m b e r of errors, t(15) -.51, position of first correct trial, t(15) = .44, nor length of longest run, t(15) = .36, was there a significant advantage for one type of game over the other. For the postvocalic liquid group, the V/ CC games were substantially more difficult than the VC/C games. The two game types differed in number of errors, t(15) = 3.67, p < .0025, one tailed, position of first correct trial, t(15) = 3.01, p < .005, one tailed, and length of longest run, t(15) = 2.65, p

< .01, one tailed. On all three measures, the V/CC games with postvocalic liquids were the most difficult of all those used in the experiment. An analysis of variance on the difference b e t w e e n the V/CC and VC/C g a m e s in number of errors revealed that this difference varied as a function of the postvocalic consonant, F(2,61) = 9.08, p < .0005. Tukey's tests showed that liquids differed significantly from both obstruents, p < .01, and nasals, p < .05. Obstruents and nasals did not differ significantly f r o m o n e another. A similar analysis on the difference between the two games in position of first correct trial showed a significant effect of postv o c a l i c c o n s o n a n t , F(2,61) = 6.14, p < .005. Again, liquids differed significantly from both obstruents, Tukey' s, p < .01, and nasals, Tukey's, p < .05. Obstruents and nasals did not differ reliably. A final analysis showed that the difference between the two games in length of longest run varied with the postvocalic consonant, F(2,61) = 5.22, p < .01. Liquids differed significantly from obstruents, Tukey's, p < .01, and apparently from nasals as well, Tukey's, p < .06. Again, obstruents and nasals did not differ significantly. In summary, the results of Experiment 4 are largely consistent with the predictions of the sonority hierarchy hypothesis. The ease of the V/CC games relative to the VC/ C games varied with the class of postvocalic c o n s o n a n t . F o r p o s t v o c a l i c ob-

FINAL CONSONANT CLUSTERS

struents, the V/CC games were significantly easier than the VC/C games. For postvocalic liquids, the V/CC games were significantly more difficult than the VC/C games. For postvocalic nasals, the two game types were indistinguishable. Liquids differed significantly from both obstruents and nasals. The differences between obstruents and nasals, although in the direction predicted by the sonority hierarchy hypothesis, were not significant. GENERAL DISCUSSION

The results of these experiments indicate that postvocalic consonants differ in their affinity with vowels. Of the consonants studied here, liquids are most closely linked with vowels. All four experiments revealed significant differences between stimuli with postvocalic liquids and stimuli with other types of postvocalic consonants. Indeed, when syllables with postvocalic liquids were presented alone subjects preferred to divide these syllables between the liquid and the final consonant (Experiment 3). They more easily learned a word game based on this division than one requiring a division between the vowel and the liquid (Experiment 4). These results support the suggestion of M a c K a y (1978) and Stemberger (1983) that postvocalic liquids are part of the peak rather than the coda. Nasals appear to occupy an intermediate position, bound with approximately equal strength to the vowel nucleus and the final consonant. Thus, Experiments 2 and 3 found no difference between V/CC and VC/ C blends for stimuli with postvocalic nasals, and Experiment 4 found no difference between V/CC and VC/C games. Finally, postvocalic obstruents are linked more closely with the final consonant than with the vowel nucleus. In Experiments 2 and 3, subjects preferred V/CC blends over VC/C blends with these stimuli. In Experiment 4, subjects more easily learned V/CC games than VC/C games when postvocalic obstruents were used. Thus, VCC syllables with postvocalic obstruents do appear to

355

have a natural boundary between the V and the final CC. The results presented here show that differences among postvocalic consonants affect subjects' performances in word game tasks. The nature of the postvocalic consonant may also be a factor in speech errors. Stemberger (1983) compared speech errors involving syllables with postv o c a l i c / 1 / a n d / r / t o errors involving syllables with other postvocalic consonants. Postvocalic /1/ and /r/ often behaved as a unit with the vowel, as in the error almost /e/most. In this error, the entire/al/unit was changed. With other postvocalic consonants, such errors were less frequent. More common were errors such as that's thap's, in which only the consonant (or only the vowel) was changed. (Stemberger also examined errors involving postvocalic glides, and reported that vowels and glides were most cohesive of all.) The present results suggest that analyses of speech errors should divide the class of nonliquid postvocalic consonants into nasals and obstruents. Nasals may more often behave as a unit with the vowel than obstruents. The present results also have implications for linguistic theories of syllable structure. They suggest that the internal structure of the rime differs depending on the phonetic category of the postvocalic consonant. The differences among postvocalic consonants found here--liquids closer to the vowel than nasals, nasals closer than obstruents--agree with the proposed sonority hierarchy (e.g., Hooper, 1976; Kiparsky, 1979; Jespersen, as reported in Malmberg, 1963; Vennemann, 1972). Until this point, evidence for a sonority hierarchy has been primarily distributional in nature. The behavioral results presented here add an additional source of converging evidence to the view that classes of consonants differ in their affinity with vowels. Theories of syllable structure, it appears, will have to take account of these differences. Vergnaud and Halle's (1979) theory does so to some extent by postu-

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lating a slot immediately after the vowel which may be occupied by sonorants but not obstruents. This proposal can account for the differences observed here between postvocalic liquids and nasals and postvocalic obstruents. The liquids and nasals are literally closer to the vowel. However, Vergnaud and Halle's (1979) proposal does not seem to account for the finding of Experiments 3 and 4 that liquids are more closely allied with the vowel than are nasals. The present studies found no evidence for the appendix as a unit of syllable structure. Subjects' divisions of the syllables in Experiments 1 and 2 did not depend on whether the final consonant could be construed as an inflectional ending. This variable may turn out to play a role in tasks different from those used here. However, it is also possible that syllable structure is a purely phonological phenomenon, not influenced by morphology. As discussed earlier, syllable structure affects the processing of speech in several ways. It influences performance in metalinguistic tasks, such as the word games of this and previous studies (Treiman, 1983); speech errors (MacKay, 1972, 1978; Stemberger, 1983); and other aspects of speech processing as well (Treiman et al., 1982). An avenue for future research is the possible influence of syllable structure on the processing of printed language. There is some evidence that syllables and intrasyllabic units are involved in the recognition of printed words for children (Katz & Feldman, 1981; Santa, 1976-1977) and for adults (Santa, Santa, & Smith, 1977; Spoehr & Smith, 1973). Studies suggest that initial consonant clusters in written words are particularly likely to serve as units of processing (Santa, 1976-1977; Santa et al., 1977). Their role may derive from the fact that they are analogous to onsets in spoken syllables. Further study is needed to specify the perceptual units in printed words and the degree to which units in printed words mirror units in spoken words.

REFERENCES CAIRNS, C. E., & FEINSTEIN, M. H. (1982). Markedness and the theory of syllable structure. Linguistic Inquiry, 13, 193-225. CHOMSKY, N., & HALLE, M. (1968). The sound pattern of English. New York: Harper & Row. FUDGE, E. C. (1969). Syllables. Journal of Linguistics, 5, 253-286. HALLE, M., & VERGNAUD,J.-R. (1980). Three dimensional phonology. Journal of Linguistic Research, 1, 83-105. HOOPER, J. B. (1976). An introduction to natural generative phonology. New York: Academic Press. KATZ, L., & FELDMAN,L. B. (1981). Linguistic coding in word recognition: Comparisons between a deep and a shallow orthography. In A. M. Lesgold & C. A. Perfetti (Eds.), Interactive processes in reading. Hillsdale, N.J.: Erlbaum. KIPARSKY, P. (1979). Metrical structure assignment is cyclic. Linguistic Inquiry, 10, 421-441. MACKAY, D. G. (1972). The structure of words and syllables: Evidence from errors in speech. Cognitive Psychology, 3, 210-227. McKAY, D. G. (1978). Speech errors inside the syllable. In A. Bell and J. B. Hooper (Eds.), Syllables and segments. Amsterdam: North-Holland. MALMBERG, B. (1963). Phonetics. New York: Dover. SANTA, C. M. (1976-1977). Spelling patterns and the development of flexible word recognition strategies. Reading Research Quarterly, 12, 125-144. SANTA,J. L., SANTA,C., & SMITH, E. E. (1977). Units of word recognition: Evidence for the use of multiple units. Perception and Psychophysics, 22, 585-591. SPOEFIR, K. T., & SMITH, E. E. (1973). The role of syllables in perceptual processing. Cognitive Psychology, 5, 71-89. STEMBERGER, J. P. (1983). The nature o f / r / a n d / 1 / i n English: Evidence from speech errors. Journal of Phonetics, 11, 139-147. TREIMAN, R. (1980). The phonemic analysis ability of preschool children. Unpublished doctoral dissertation, University of Pennsylvania. TREIMAN, R. (1983). The structure of spoken syllables: Evidence from novel word games. Cognition, 15, 49-74. TREIMAN, R., SALASOO, A., SLOWIACZEK, L. M., & PISONI, D. B. (1982). Effects of syllable structure on adults" phoneme monitoring performance. (Progress Report No. 8). Bloomington: Indiana University, Speech Research Laboratory. VENNEMANN,T. (1972). On the theory of syllabic phonology. Linguistische Berichte, 18, 1-18. VERGNAUD,J.-R., & HALLE, M. (1979). Metrical phonology. Unpublished manuscript, Department of Linguistics, MIT. (Received April 1, 1983) (Revision received May 7, 1983)