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The perceptual basis of consonant cluster reduction and final devoicing*
Journal of Phonetics (1980) 8, 259-268
The perceptual basis of consonant cluster reduction and final devoicing* Frank Parker t Department of English, The University of British Columbia, 2075 Westbrook Hall, Vancouver, B .C., Canada Received 12th October 1978
Abstract:
Recent studies have indicated that phonological change is a direct function of the acoustic cues for the segments involved. Here it is argued that cues for the voicing characteristic of the final postvocalic and post-nasal stops and cues for final nasals can be ranked according to relative "strength". That is, cues for final voiced stops are weaker than those for final voiceless stops, which are in turn weaker than those for final nasals. This hypothesis is incorporated into a view of sound change which assumes ( 1) that consonant cues are carried by adjacent vowels, (2) that vowel reduction and loss weaken and obliterate these cues, and (3) that consonants with weak cues are replaced by homorganic consonants with stronger cues. This theory makes predictions about the direction of change and helps account for changes, such as the following, which have occurred during the history of German : /ding/~ I dii)k/ ~ /dlrJ/ . In addition, this theory is applied to a range of devoicing and consonant cluster reduction phenomena, including the widespread tendency among the languages of the world to devoice stops in final position, the loss of final voiceless stops in dialects of Chinese, and the absence of final /mb/ - /f)g/ and /lb/ - flgf clusters in English.
Perceptual basis of consonant cluster reduction and final devoicing Descriptions of phonological change within generative grammar specify segments in terms of distinctive features (DFs). Such segments are then said to be inserted, deleted, or modified in a given environment. For example, devoicing of a stop in fmal position would be characterized as +obstruent ~ [ - voice] I ___jf. - co.ntinuant [ + vmce Such descriptions alone, however, rarely provide explanations of how and why phonology changes . Thus, it is not surprising that generative analyses have been the subject of criticism recently. For example, Chen & Wang state, " . . . while the application of the generative model to historical phonology has stimulated remarkable advances in our ability to state "diachronic correspondences", it has shed precious little light on the mechanism of phonetic change" (1975: p. 265). The reason that generative descriptions in terms of DFs do not explain change is fairly straightforward . First, phonological change is typically context*This work was supported, in part, by a University of British Columbia Humanities and Social Services Grant. t Present address: Linguistics Programme, Louisiana State University, Allen Hall, Baton Rouge, LA. U.S.A. 0095-4470/80/030259+10 $02 .00/0 ©1980 Academic Press Inc. (London) Ltd.
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dependent, but the specification of segments in terms of DFs is not. For example, in English [b] in certain positions has been lost: comb < OE camb [kamb] . In other positions, [b] has been devoiced: unkempt< OE cemban. In still other positions, [b] has remained unchanged : bare < OE baer and stub
[
~-coronal ~~~;i~:n:n]
+anterior +voice Second , change must to some extent be considered a function of the physical speech signal , since it is the one facet of language that the speaker (in particular , the language learner) has direct access to . After exposure to the signal, the speaker apparently internalizes a phonology based on the inferences he makes about its structure (Andersen 1973 : pp. 776-778 ; Parker 1977a, b). Yet DFs are not part of that signal. It has been shown repeatedly that " . . . . . the formal properties of phones considered as perceptual entities [that is, in terms of DFs] are very different from the . formal properties of phones considered as acoustic events (Fodor, Bever & Garrett 1974: p. 299). Moreover , this finding has been shown to hold for infants as well as adults . Eilers concludes from her study of speech perception in infants " . . . that a model of infant speech perception which assumes innate detectors for abstract linguistic features fails to account for the infants' differential treatment of the abstract features in a variety of concrete acoustic phonetic contexts" (I 977 : p.l335). In other words , since infants can discriminate between two segments in one phonetic context but not in another , they apparently are not responding directly to DFs. It may be, then , that what is missing in generative analyses of phonological change is careful consideration of acoustic cues (ACs). First, ACs, like changes in phonology, do vary according to context (Liberman eta!. 1967; Parker 1977a, b). Second, ACs, not DFs, are what speakers actually hear. Acoustic cues are properties of the speech signal by means of which speakers recover phonological segments from the speech stream ; DFs are categories in terms of which speakers organize phonological segments once they have been recovered .--from the speech signal (Parker 1977b ). Let's consider a specific example of phonological change which an abstract analysis in terms of DFs can describe but not explain. In German, voiced stops after nasals have been devoiced and/or deleted. In particular compare the development of /IJg/clusters in Northern German (NG) and in Standard German (SG) to the relative stability of /l)k/ clusters in these dialects. /I}g/ (NG) /fJg/ (SG) Ding sing. pl. sing. pl. "thing" /dll)g/ /dlt}ga/ /dll)g/ /diT)ga/ /dlt}k/ /dll)k/ /dlt}a/ /diT)a/ /dlt}/ /T)k/ (NG and SG) Fink sing. pl. "finch" /flr)k/ /flt}bn/ The /T)g/ sequences have undergone three changes :
o) /g/
---+
(2) /k/ - (3) /g/ - - -)
~
I ITJI _ # I /I)/ __#in SG, wherever /k/ < /g/
~
I
/kl
fiJI _fa/.
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These phenomena have been discussed by a number of investigators, most notably Kiparsky (1972), Hooper (1976), and Vennemann (1970, 1974). Kiparsky claims that the dialects in question have an underlying post-nasal /g/, but that through time German has added two ordered rules to its grammar: (i) a rule that devoices all final and pre-consonantal obstruents and (ii) a rule that deletes /g/ after a nasal. He accounts for the difference between NG and SG by hypothesizing that the rules were reordered in SG so that /g/ -deletion applies before devoicing (1972: pp. 209-210). Although this is a clear characterization of German phonology at different points in space and time, Hooper notes that "Rule reordering is a description of a particular linguistic change but, in itself, not an explanation" (1976: p. 92). Hooper, I think, is correct; it is not at all clear what would motivate a speaker to spontaneously reorder two rules in his grammar. Hooper, however, does not attempt to explain the changes that have occurred; rather, she argues against Kiparsky's claim that there is an underlying /g/ in both dialects of German. Hooper, who takes her analysis from Venneman (1974), proposes that NG has an underlying /k/ inserted by an "arbitrary" morphophonemic rule but that SG has neither a /g/ nor a /k/ in its underlying representation (1976: pp. 95, 97). Although her analysis is preferable to Kiparsky's in that she assumes that a speaker would be constrained from internalizing an underlying form that contains a segment which never appears phonetically (Vennemann's Strong Naturalness Condition), she still avoids the question of what caused the change in the first place. She claims that the two rules, devoicing and /g/-deletion, were simply "added" to the grammar of German (1976: p. 97). Vennemann, on the other hand, does "attempt an explanation" of the /g/-deletion phenomenon; he notes that fg/ is deleted after a nasal when the /g/ occurs before zero stress (1970 : p; 74). This solution, however, is incomplete in two respects. First, it does not deal with the de voicing of /g/ to /k/, and , second, it is simply a statement of the conditioning environment for /g/-deletion; it does not explain the relationship between /g/-deletion and zero stress. Since the generative analyses do not seem to shed much light on the actual mechanism of phonological change, it might be worthwhile to examine the German data in terms of ACs. The ACs relevant here are those for fmal post-vocalic stops (as in cat - cad), postnasal stops (as in can't- canned), and post-vocalic nasals (as in can).' It is generally agreed that stop release in fmal position is sufficient to discriminate between voiced and voiceless stops (Malecot 1958: p . 379; Wang 1967: p. 343). However, it is also known that stops in final position may be, and in fact usually are, unreleased (Francis, 1958: p. 73 : Chen & Wang, 1975 : p. 270; Umeda & Coket,.- 1975: p. 545). In the case of unreleased post-vocalic stops, the voice value is signalled by the manner in which the preceding vowel is terminated (Parker, 1974) 2 . That is, a post-vocalic voiceless stop is cued by abrupt termination of the preceding vowel and a post-vocalic voiced stop is signalled by gradual termination of the preceding vowel. "Termination" as used here is defined in terms of the period of vocal cord 1
The work on ACs cited here is primarily from English. However, since German and English are both Germanic languages and thus share much of their historical development, the principles governing the ACs for English stops and nasals will be assumed to hold for German. 2
1t is often maintained that preceding vowel length cues the voice value of a following stop. (See Parker, 1974: p. 212 for references.) However, historical evidence indicates that vowel length is not a stable cue. For example, differences in vowel length in Chinese were quickly reinterpreteo as distinctive pitch contours, and vowel length differences in Sanskrit and Vulgar Latin were superceded by qualitative differences in vowel height (Chen & Wang, 1975 : pp . 272-273). Moreover, Eilers (1977) finds that infants are able to discriminate between post-vocalic /d/ and /t/ even when the length of the preceding vowel is held constant. Such phenomena indicate that vowel length is not crucial for the perception of voicing in post-vocalic stops.
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vibration during the transition from vowel to stop. Before a voiced stop the period gradually lengthens; no such change occurs before a voiceless stop (Parker, 1974: p. 218). In fact, fmal post-vocalic voiceless stops in English are regularly produced with complete glottal closure (Umeda & Coker, 1975: p. 545), which causes abrupt terrilination of the preceding vowel. 3 Moreover, gradual vowel termination, unlike abrupt termination, is an ambiguous AC. A vowel in fmal position, as well as a vowel preceding a voiced stop, exhibits period lengthening. If a post-vocalic voiced stop is unreleased as in cued [kjud'] , it is often confused with a vowel-final utterance such as cue [kju] (Parker, 1974: p. 217). 4 The situation is even more complex with ACs for post-nasal stoRs. If a nasal is followed by a voiceless stop, the vowel becomes nasalized and the nasal segment drops out. That is, can't /kcent/, for example, becomes [kret] phonetically (Malecot, 1960: Parker, 1977a). Thus, a post-nasal voiceless stop has the same AC as a post-vocalic voiceless stop- abrupt termination of the preceding vowel; the only difference between such utterances is in the nasalization of the preceding vowel. On the other hand, the nasal preceding a voiced stop does not drop out phonetically; that is, canned /kcend/ becomes [krend] phonetically (Malecot, 1960 : Parker, 1977a). The AC for a post-nasal voiced stop, then, cannot be gradual vowel termination, since such a stop is not directly preceded by a vowel. Instead, a post-nasal voiced stop is cued only by its release; if it is not released, it is acoustically similar to an utterance without a stop. That is canned [krend'] is acoustically the same as can [kren') (Parker1977a: p. 102). The ACs for post-vocalic nasals in final position are not nearly as sensitive to context as are the ACs for fmal, post-vocalic and post-nasal stops. Nasal segments are signalled by a single bar of low frequency resonant energy and a complete lack of high frequency energy (Cole & Scott 1974: p. 353) . Thus, because of their vowel-like spectral qualities, nasals have stronger ACs than do stops, in final position (Chen & Wang, 1975: p. 270- 1). Two significant facts emerge from this discussion of ACs. Not only are ACs (especially those for stops) highly context-dependent, but also they vary in their relative strength and ambiguity. If we restrict our discussion to the ACs for final, unreleased 5 stops and nasals, we can rank these cues as follows. (Let V =vowel, N =nasal, and C =stop.) The cues for fmal voiced stops,.then, are weaker than those for final voiceless stops, which in turn are weaker than those for final nasals. (Here an ambiguous cue is assumed to be weaker than an unambiguous cue.) 3
Additional support for this cue is provided by the historical development of Chinese Chen & Wang (1975: p. 267) note that in the process of losing final post-vocalic voiceless stops, Chinese went through a stage where all the voiceless stops reduced to a glottal stop . This is clearly no accident. A postvocalic glottal stop per se forces abrupt termination of the preceding vowel. The vocal folds are brought together quickly by mechanical means rather than being allowed to come to rest by gradual obstruction of the airflow in the oral cavity (Parker, 1974: pp. 216-217). The fact that post-vocalic voiceless stops reduce to a glottal stop suggests that the AC for all of them is the same, abrupt termination of the preceding vowel. 4
There is historical evidence that just such 'confusability' causes change . For example, OE daeg 'day' comes from West Germanicdag /dag/ and thus originally ended in a voiced palatal stop [.t 1. (Here [.t 1 /g/ as a result of the fronting effect of the vowel (ae 1.) The fact that Mod .E. day has no final voiced stop can be explained as follows. If [ t 1 is released, a stop is clearly perceptible; if it is not released the gradual termination of the vowel may be perceived as a vowel (or in this case a glide). Thus, we have the following progression: /daeg/ - - - 4 (dae ----+ (dae .t7 ] - - 4 [daej I - - 4 (dej 1. (The change in vowel quality is irrelevant to this discussion.) 5 Since all of the segments under consideration may be unreleased, I will assume that this limiting case obtains throughout the discussion. It should be noted, however, that all final released stops and nasal have "stronger" ACs than their unreleased counterparts (Wang, 1967: p. 348).
<
;n
Consonant cluster reduction and final devoicing Strongest - VN
vc
- (can [kren1 ] -(cat [ka£]
263
- ACs present throughout vowel and closure -one unambiguous cue, abrupt vowel termination
[-vee] VNC
-(can't
[~t']
- same as above
[-vee]
vc
- (cad [ka:d']
-one ambiguous cue, gradual vowel termination
[+vee] Weakest
VNC
-(canned [krend7 ] - no AC
[+vee] Moreover, if we view phonological change as a function of ACs, it is reasonable to expect that those segments with relatively "weak" ACs will be most likely to undergo change; what's more, we would expect change to proceed from weak to strong. That is, we might expect canned to become can't and can't to become can, but not vice versa. The directionality of change is, however, only part of the picture. It is also necessary to determine what causes the appearance of acoustically unstable segments in the first place. For the purposes of illustration, let's assume the simplest, most "natural" type of syllable structure- cl vI c2 v2 c3 v3' (see Shane, 1973: pp. 52-3). When stress becomes fixed on the first syllable (as has occurred in all the Germanic languages), the unstressed vowels are reduced and eventually lost; that is, cl v 1c2 v2c3 v3~ cl VI c2 ac3 a~ cl vI c2 ac3~ cl vI c2 c3. Since, as we have seen, the ACs for stops are carried by neighboring vowels, then loss of the final [a] removes half of the potential cues for C3 and loss of the preceding [a] obliterates the remaining cues for C3 as well as half the cues for C2 . Thus, after the unstressed vowels are reduced and deleted, tha ranking of C1 - C3 in terms of the relative strength of their ACs is C1 -strongest, C2 -weaker, and C3 - weakest. This provides us with a complete (if somewhat oversimplified) model of phonological change: fixed stress causes vowel reduction and deletion, which in tum causes weakening of ACs for the neighboring consonants. Those consonants with weak ACs are replaced by segments with stronger ACs. Let's now return to the problem of explaining the three changes that have occurred in German. The first change is the devoicing of post-nasal stops in fmal position, specifically /g/ ~ /k/ / /ql-- ~ We must begin by putting this phenomenon into its historical context. First, the proto-forms for members of theDinge-Dinge and Fink-Finken paradigms originally had a full vowel following the nasal + stop clusters; we may assume this, because in IndoEuropean, nouns typically ended in a non-reduced vowel or carried an inflectional suffixbeginning with such a vowel (Misra, 1968: pp. 52-60). The reconstructed forms then are /dlTjgV/-/diqgV/ and /flqkV/-/fiTJkVn/. (The exact quality of the vowel is unimportant). Second, these vowels eventually reduced to ral, due to the fixed stress on the first syllable of native words. (See MacCarthy, 1975: p. 10). Thus, the proto-forms reduced to /ding e//dlrpy,f and /flrJka/-/fii)kan/, respectively . Third, the Ac for the /g/ in the ding paradigm, but not that for the /k/ in the fink paradigm, is carried by the [a] . Stop release in fmal position constitutes an incipient centralized vowel; that is, [C-] = [Ca] (Parker, 1977a: p. 103). Therefore, since the AC for a post-nasal voiced stop is release, and since release = [a], then the AC for the /g/ in /dlqga/ must be [a]. Fourth, eventually the final [a] in the singular was lost. 6 This created an acoustically unstable situation, since it in essence deprived all final post-nasal voiced stops of their AC. 7 6
Loss of final [a] is a widespread phenomenon.lt has occurred in all the Germanic languages (Lehmann, (1962: p. 161; Hooper, 1976: p. 102) and Galla-Romance (Chen & Wang, 1975: p. 269; Hooper, 1976: p. 104-5). 7
The effect was considerable. Stampe notes that loss ofword.final [aj 's in German caused "thousands" of voiced stops to show up in final position (1969: 453).
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F. Parker
Three possibilities existed to compensate for this unstable situation. (1) The stop could simply have been released. However, this apparently was not a viable alternative since release would contradict the general loss of fmal [a] . That is, since [C a] = [C) .loss of final [a] necessitates nonrelease of the stop. Moreover, releasing the stop would cause the singular and plural forms to fall together. That is, since [dh)g-) and [dlr)ga] are similar acoustically, the singular/plural distinction would have been obliterated for all nouns of the Ding-Dinge paradigm. 8 (2) The stop could have been lost. That is, [dlrjg ] might have become /dii]/. Why it did not is somewhat unclear. However, we have to assume that although simple loss of /g/ was a viable alternative, it simply did not occur. It is worth noting that in English, where the same phonetic conditions obtained, voiced velar and labial stops were lost after nasals . For example,in Mod. E. we have climb /klaim/
is worth noting that German apparently did prefer the 'release' solution in the Bunde-Bundes paradigm in dialects of NG, where final voiceless stops have been revoiced as in [bUnd- ] - (bUnd:ls] ,(see Kiparsky, 1968: p. 177). Note, however, that release of the /d/ in final position does not cause the singular and plural to fall together, since this paradigm has fmalf;-,s/ rathen than f;-,•f in the plural.
Consonant cluster reduction and final devoicing
265
variably by speakers of languages such as Tamil, Japanese, and Italian (pers. comm.) The explanation for this phenomenon is similar to that for the German data. Post-vocalic voiced stops have two cues: release and gradual termination of the preceding vowel. The pronunciation [d:Jg:l] represents dependence on the release cue. When unreleased, however; a post-vocalic voiced stop is not only reduced to a single cue, gradual vowel termination, but an ambiguous cue at that. Thus, for a speaker to preserve the stop without having to release it and without having to depend on an ambiguous cue, he may signal it unambiguously by abrupt termination of the preceding vowel. This, of course, entails devoicing the stop. course, entails devoicing the stop. Note, in addition , that the widespread tendency for languages to devoice fmal stops (King, 1976 : p. 29; Stampe. 1969 : p. 445; Marcari, in press) can be accounted for by this analysis. A final unreleased post-vocalic voiced stop has one, ambiguous cue-gradual vowel termination; a voiceless stop in the same phonetic context has one unambiguous cue-abrupt vowel termination. Thus, devoicing a final. post-vocalic stop in essence "strengthens" its AC. Let's now consider the second phonological change illustrated by the German data- the loss of post-nasal voiceless stops in fmal position in SG . In particular, post-nasal /k/ was deleted in final position sometime after the Middle High German period, changing ding from /di!Jk/ to /dlq/ . The primary force effecting the loss of /k/ is the relative weakness of abrupt vowel termination .as the AC for post-vocalic stops. (Recall that /dlqk/ reduces to [dik] phonetically). We know that unreleased stops are harder to perceive than nasals in the same articulatory position (Chen & Wang, 1975 : pp. 270-271). Thus, the AC for the fmal segment in [dik7 ) is weaker than that for the fmal segment in [dl'ij 7 ], We may hypothesize that even though the listener was exposed to [dlk 7 ] , he assigned the utterance the structure [diiJ 7 ] because the cue for the nasal is stronger than that for the stop. The speaker then internalized the underlying form /dlf)/. Still it remains to be shown why the /k/ was lost in the ding paradigm but not in the fink paradigm . That is , /k/ was lost in final position after a nasal, but only where /k/ was historically derived from /g/. Even though we have to assume that both /k/'s were acoustically identical, the cause for such "selective" change may be found in paradigm pressure. That is, a /k/ occurred in the plural of the fink paradigm {/flqk:ln/) but not in that of the ding paradigm {/dhp/). Although the ACs for both /k/s were weak, the /k/ in fink could be reconstructed on the basis of the /k/ in fznken; whereas the /k/ in ding was lost since there was no velar stop in dinge to serve as a model. German provides other examples of similar phenomena. For example, hintbere in Old High German shows up as Himbere in SG. The /t/ is unreleased because 7it is followed by another obstruent, (see Wang, 1967: p. 343). Therefore, the only AC for [t ] is abrupt vowel termination. Because of the weakness of the cue, the (t 7 ] was apparently not perceived by new speakers and thus was not internalized as part of the base form of hintbere. In the absence of the /t/, the nasal was free to assimilate to the point of articulation of the /b/ . . In addition, Bithell notes ,.''Omission of the [t] in und is very common in word groups in conversation: kurz und gut (kurts un gu :t]" {1952 : p. 197). The point of interest here is not the accuracy of Bithell's observation, but rather what it reveals about the relative strength of abrupt vowel termination as an AC . We know that und does have an underlying stop. It occurs in slow careful speech and before vowels. Thus, it may be more accurate to say that even though German speakers do produce the final /t/ in und, listeners typically do not perceive it because of the weakness of its AC when 11nreleased, as it is before a consonant. Moreover, the loss of final, unreleased voiceless stops is not restricted to German. This phenomenon is, in fact, fairly widespread . For instance, as mentioned above, Chen and Wang discuss the different stages of the loss of such stops in different dialects of Chinese, (see footnote 3). This can be explained as a function of the relative weakness of abrupt vowel termination as an AC. Final voiceless stops were unreleased in Chinese, and because of the relative weakness of the single cue, the stops were no longer perceived and were eventually lost.
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F. Parker
Let us now consider the third and fmal change illustrated by the German data: the loss of voiced stops between a nasal and a following vowel. Such a change occurred in the plural of dinge, where /diqga/ became /dlrp/. It will be noted, however, that the analysis of the other two changes in German would predict that loss of post-nasal /g/ before Jaj should NOT occur, since the AC for the stop is release and release = [a] . Nevertheless, there are extenuating circumstances that must be considered in order to bring this phenomenon in line with the analysis of the other two changes. First, we may assume that the /g/ in dinge was syllable initial in Proto-Germanic, since it occurred before a full vowel. Venneman notes that "In Ingrid, Anglia, Anglist, as well as in Tango [where /g/ precedes a full vowel], the /g/ belongs in the following syllable, while [word fmally and before a consonant or I a/] it is more closely allied with the preceding syllable as a consequence of zero stress" (1970: p. 74). That is, post-nasal /g/ preceding a full vowel constitutes the onset of that syllable, and elsewhere it forms the coda of the preceding syllable . Thus, we can assume that the ProtoGermanic form of Dinge was /diq$gV/. 9 ($=syllable boundary). Second, since syllabicity is apparently dependent on stress, we may assume that a change in stress can effect a change in syllabicity. When a vowel becomes unstressed, the preceding consonant may become the coda of the preceding syllable. For example, compare the syllable structure of the following pairs of words: economics /ikaSriamlks/, economy /ikan$ami/ and psychology /sai$kalaji/, psychological /salk$ alajekal/. (Note that economics */i.kan$amlks/ and psychology* /salk$:HaYi/ are both unacceptable since the consonants /n/ and /k/ respectively are analyzed as part of the preceding syllable when the following vowels are stressed). The change in syllabicity becomes clear when we consider the shortened forms of these words: econ /ikan/ and psych /salk/. In these examples, it is obvious that the /n/ and the /k/ have been reanalyzed as part of the preceding syllables. Moreover, compare sentential and sentence. In the former there is a clear syllable boundary between the first /n/ and the following /t/: [sln$tfncal]. On the other hand, in sentence the /t/ may reduce to [7], and we get [si?$?ts]. We can deduce that the syllable boundary comes between [?] and [n], since we have already seen that [?] constitutes abrupt termination of a preceding vowel, (see footnote 3). Because a vowel and its termination are inseparable, the glottal stop must be part of the same syllable as the preceding vowel. Thus, from this type of data we can conclude that when the fmal vowel in dinge became unstressed and reduced to [a] , this could cause the syllable boundary to shift so that /dlr).$gV/ became /diqg$a/. (For a detailed discussion of the effects of stress on syllabicity see Parker, in press.) lengthened before /mb, nd, ld, rd, r'J/ except when a third consonant followed (Pyles, 1971 pp. 163-164). Therefore, in OE we have cild /clld/ and cildren /Clldr!n/, but in Mod. E. we have child and children. The vowel in the singular has been lengthened and raised. The fact that this change has occurred in the singular but not in the plural must be a function of syllabicity, since that is the only difference between the environments of the vowels in the two words. In cild the /1/ and /d/ are in the same syllable (/clld$/) but in cildren they may be in different syllables (/W$dr€n/). Thus, lengthening apparently operated in vowels preceding preceding /ld'$/ but not on those before /l$d/. 10 9
Actually, the /f)/ may not have been velarized in the protoform, since IndoEuropean is not known to have had /n/ (Lehmann, 1955: pp. 7 -8). /n/ is probably the result of assimilation to the place of articulation of the following velar; however, this need not concern us here. 10
It is worth mentioning that this same data provides evidence that syllabicity changes back and forth through time . Vowel lengthening before the consonant clusters mentioned above was unstable. Vowels in these environments lengthened and then shortened in some words. For example, compare wind (noun) and friend, in which the vowel has reshortened, to wind (verb) and fiend, in which the vowel has remained long (Pyles, 1971: pp. 163-164).
Consonant cluster reduction and final devoicing
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Finally, the AC for a syllable-final post-nasal voiced stop seems to be the same as that for one in final position, namely release. This is because the same articulatory and acoustic conditions obtain for both. Note that if a syllable-fmal post-nasal voiced stop is released, an intrusive [ "] results. For example [af)g-$a] becomes something like [al)g"a] phonetically. On the other hand, if the stop is not released, it,just like its word-fmal counterpart, has no AC and thus is not perceptible . That is, for instance, [aiJg7 $a] reduces to [an!J$a]. which appears as [aiJa] phonetically. Thus, a syllable-final post-nasal voiced stop is in much the same sort of acoustically unstable position that a word fmal post-nasal voiced stop is. We now have enough information to suggest an explanation for the loss of /g/ in Dinge. The change can be reconstructed as follows: [di!J$gV] -proto-form [dlrj$g"] -vowel reduction [di!Jg$"] -loss of stress causes resyllabification [dh}g' a] - fg/ is unreleased in syllable-final position: [g 7 ] has no AC after a nasal - [g7 ] is not perceptible, since it has no AC [dlt)0"] -fg/ is not stored in the grammars of n:ew speakers, since they do not [dbp] perceive it. This account of the Joss of /g/ in Dinge is applicable to a variety of similar changes in a number of languages. For example, the same phenomenon occurs in some dialects of English as well as in rapid speech, as in finger [fiiJ"r] , longer [biJ"r] , and strongest [str:>IJ"St] . Moreover, Bithell notes that "In Plattdeutsch these assimilations are the rule : go/len= golden, . . . finnen = finden. We find this assimilation in popular orthography (which correctly reproduces the sound heard): in nachtschafener Zeit (for -ender)" (1952: p. 193). These so-called "assimilations" can be explained exactly the same way as the loss of fgf in dinge : the voiced stop is unreleased in syllable-fmal position, and an unreleased voiced stop has no AC after a nasal or a lateral. Note, in this same vein, the scarcity of fmal /lb/ and /lg/ clusters in English; I can think of only bulb. On the other hand, final /lp/ and /lk/ clusters are common, for example, gulp, pulp, help, kelp, scalp, and hulk, sulk, milk, silk, bulk, etc. (The common occurrence of final /ld/ clusters results from morphological pressure. /d/ is one of two productive past tense inflections in English, and thus must be retained even in what are relatively unstable acoustic environments (Parker 1977a: p. 104).) Furthermore , this analysis accounts for some related phenomena. For example, it helps explain why in English we can delete /g/ in English [IIJlls] but not in Angola * [aei)ol ;i] . In English the /g/ precedes an unstressed segment and thus may be analyzed as syllable-fmal; in Angola it precedes a stressed segment and therefore must be analyzed as syllable-initial. In the former the /g/ must be unreleased . In addition, the explanation proposed here accounts for Vennemann's observation that "Strictly speaking, there never was an historical process of g-deletion. The segments /g/ and /b/ in the clusters /J}g/ and /mb/ were assimilatorily nasalized; the resulting /mm/ and /rm/ were later degerninated ... " (1974 : p. 214). The unreleased /g/ in syllable fmal [1Jg 7 ] clusters, although not perceptible as a stop, was perceptible as a lengthening of the nasal. That is, [l)g 7 ] is phonetically similar to [r)l)] . The 'long' nasal was shortened because length is not distinctive in German consonants. Finally, this analysis accounts for the retention of post-nasal /k/ in finken as well as the loss of the post-nasal /g/ in dinge . Even if resyllabification took place within the /k/ paradigm, it would not obliterate the AC for /k/ since before a voiceless stop the nasal drops out and the cue for the stop is carried by the preceding vowel. That'is. /diry$gV/ becomes [dlr)g7 $"] , but /flr)$kVn/ becomes /fik'$;}n/. In summary, the analysis presented here is more than simply an attempt to account for three changes in German phonology. It is rather an effort to show, fust, that phonological change cannot be fully understood without reference to ACs. Such cues are contextdependent just as phonological change is, and ACs are the elements of the signal by means
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of which speakers· recover phonological segments. Second, ACs form part of a general paradigm of ·phonological change. Fixed stress causes vowel reduction and eventual deletion. Vowel loss in turn introduces consonants (in particular stops) into acoustically unstable positions by eliminating the environments that carry their cues. Third, the direction of phonological change is a function of the relative strength of the Acs for the segment involved. Segments with relatively weak ACs tend to be transformed into segments with stronger AC's. In particular, the cues for final voiced stops are weaker than those for fmal voiceless stops, which in tum are weaker than those for fmal nasals . The German data discussed here exemplify this general progression : /dlf)g/ --+ /dlr)k/ --+ /dlf)/. References Andersen, H. (1973). Abductive and deductive change. Language 49,765 - 793 . Bithell, J . (1952). German Pronunciation and Phonology. London: Metheun & Co . Chen, M. Y. & Wang, S. Y. (1975) . Sound change :actuation and implementation. Language 51 , 255-281. Cole, R. & Scott, B. (1974) . Toward a theory of speech perception. Psychological Review 81, 348 - 374 . Eilers, R . E. (1977). Context-5ensitive perception of naturally produced stop and fricative consonants by infants. Journal of the Acoustical Society of America 61, 1321 - 1336. Fodor, J., Bever, T ., & Garrett, M. (1974). The Psychology of Language . New York : McGraw-Hill. Francis, W. N. (1958) . The Structure of American English. New York : Ronald Press. Hooper, J. (1976) . An Introduction to Natural Generative Phonology. New York: Academic Press. King, R . D. (1976) . The History of Final Devoicing in Yiddish . Bloomington : Indiana University Linguistics Club. Kiparsky, P. (1968). Linguistic universals and linguistic change. Universals in LinKUistic Theory. Back, E. & Harms, R. (Eds.) . New York: Holt , Rinehart & Winston, 171-202 New York : Holt, Rinehart & Winston. KiparSky, P. (1972). Explanation in phonology. In On the Goals of Linguistic Theory, (Peters, S. Ed.), pp . 189-227. Englewood Cliffs, New Jersey: Prentice-Hall. Lehmann, W. P. (1955). Proto-Indo-European Phonology. Austin: University of Texas Press and the Linguistic Society of America . Lehmann, W. P. (1962). Historical Linguistics. New York: Holt, Rinehart & Winston. Liberman, A. M., Cooper, F. S., Shankweiler, D. P, & Studdert-Kennedy, M. (1967). Perception of the speech code . Psychological Review 74,431 - 461. Macari, N. Some psychophysical evidence for natural phonological processes. Journal of Phonetics. (In press). MacCarthy, P. (1975). The Pronunciation of German . London: Oxford University Press. Malecot, A. (1958) . The role of releases in the identification of released final stops. Language .34, 370-380. Malecot , A. (1960). Vowel nasality as a distinctive feature in American English. Language 36, 222 - 229. Misra, S. S·;·(i 968) . A ·Comparative Grammar of Sanskrit, Greek, and Hittite. Calcutta: The World Press . Parker, F. (1974). The coarticulation of vowels and stop consonants. Journal of Phonetics 2, 211 - 221 . Parker, F. (1977a) . Perceptual cues and phonological change . Journal of Phonetics 5, 97 - 105. Parker, F . (1977b) . Distinctive features and acoustic cues: Journal of the Acoustical Society of America Parker, F. (in press). Resyllabification and phonological change. Journal of Phonetics. Pyles, T . (1971) . The Origins and Development of the English Language. New York : Harcourt, Brace, Jovanovich. Schane, S. (1973) . Generative Phonology. Englewood Cliffs, New Jersey: Prentice-Hall. Stampe, D. (1969) . The acquisition of phonetic representation. Chicago Linguistic Society 5, 443 - 454. Umeda, N. & Coker, C. H. (1975). Subphonemic details in American English. In Auditory Analysis and Perception of Speech. (Fant, G. & Tatham, M., Eds). Pp. 539-564. New York : Academic Press. Vennemann,-T. (1970). The German velar nasal: a case for abstract phonology. Phonetica 22, 65-81 . Vennemann, T . (1974). Phonological concreteness in natural generative grammar. In Towards Tommorrow's Linguistics. (Shuy, R. & Bailey, C., Eds). Pp. 202-219 . Washington: Georgetown University Press. Wang, S. Y. (1967). Tr-ansition and release as perceptual cues for final plosives. In Reading in Acoustic Phonetics. (Lehiste; 1., Ed .). Pp. 343-350. Cambridge, Massachusetts : MIT Press.
The perceptual basis of consonant cluster reduction and final devoicing* Frank Parker t Department of English, The University of British Columbia, 2075 Westbrook Hall, Vancouver, B .C., Canada Received 12th October 1978
Abstract:
Recent studies have indicated that phonological change is a direct function of the acoustic cues for the segments involved. Here it is argued that cues for the voicing characteristic of the final postvocalic and post-nasal stops and cues for final nasals can be ranked according to relative "strength". That is, cues for final voiced stops are weaker than those for final voiceless stops, which are in turn weaker than those for final nasals. This hypothesis is incorporated into a view of sound change which assumes ( 1) that consonant cues are carried by adjacent vowels, (2) that vowel reduction and loss weaken and obliterate these cues, and (3) that consonants with weak cues are replaced by homorganic consonants with stronger cues. This theory makes predictions about the direction of change and helps account for changes, such as the following, which have occurred during the history of German : /ding/~ I dii)k/ ~ /dlrJ/ . In addition, this theory is applied to a range of devoicing and consonant cluster reduction phenomena, including the widespread tendency among the languages of the world to devoice stops in final position, the loss of final voiceless stops in dialects of Chinese, and the absence of final /mb/ - /f)g/ and /lb/ - flgf clusters in English.
Perceptual basis of consonant cluster reduction and final devoicing Descriptions of phonological change within generative grammar specify segments in terms of distinctive features (DFs). Such segments are then said to be inserted, deleted, or modified in a given environment. For example, devoicing of a stop in fmal position would be characterized as +obstruent ~ [ - voice] I ___jf. - co.ntinuant [ + vmce Such descriptions alone, however, rarely provide explanations of how and why phonology changes . Thus, it is not surprising that generative analyses have been the subject of criticism recently. For example, Chen & Wang state, " . . . while the application of the generative model to historical phonology has stimulated remarkable advances in our ability to state "diachronic correspondences", it has shed precious little light on the mechanism of phonetic change" (1975: p. 265). The reason that generative descriptions in terms of DFs do not explain change is fairly straightforward . First, phonological change is typically context*This work was supported, in part, by a University of British Columbia Humanities and Social Services Grant. t Present address: Linguistics Programme, Louisiana State University, Allen Hall, Baton Rouge, LA. U.S.A. 0095-4470/80/030259+10 $02 .00/0 ©1980 Academic Press Inc. (London) Ltd.
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dependent, but the specification of segments in terms of DFs is not. For example, in English [b] in certain positions has been lost: comb < OE camb [kamb] . In other positions, [b] has been devoiced: unkempt< OE cemban. In still other positions, [b] has remained unchanged : bare < OE baer and stub
[
~-coronal ~~~;i~:n:n]
+anterior +voice Second , change must to some extent be considered a function of the physical speech signal , since it is the one facet of language that the speaker (in particular , the language learner) has direct access to . After exposure to the signal, the speaker apparently internalizes a phonology based on the inferences he makes about its structure (Andersen 1973 : pp. 776-778 ; Parker 1977a, b). Yet DFs are not part of that signal. It has been shown repeatedly that " . . . . . the formal properties of phones considered as perceptual entities [that is, in terms of DFs] are very different from the . formal properties of phones considered as acoustic events (Fodor, Bever & Garrett 1974: p. 299). Moreover , this finding has been shown to hold for infants as well as adults . Eilers concludes from her study of speech perception in infants " . . . that a model of infant speech perception which assumes innate detectors for abstract linguistic features fails to account for the infants' differential treatment of the abstract features in a variety of concrete acoustic phonetic contexts" (I 977 : p.l335). In other words , since infants can discriminate between two segments in one phonetic context but not in another , they apparently are not responding directly to DFs. It may be, then , that what is missing in generative analyses of phonological change is careful consideration of acoustic cues (ACs). First, ACs, like changes in phonology, do vary according to context (Liberman eta!. 1967; Parker 1977a, b). Second, ACs, not DFs, are what speakers actually hear. Acoustic cues are properties of the speech signal by means of which speakers recover phonological segments from the speech stream ; DFs are categories in terms of which speakers organize phonological segments once they have been recovered .--from the speech signal (Parker 1977b ). Let's consider a specific example of phonological change which an abstract analysis in terms of DFs can describe but not explain. In German, voiced stops after nasals have been devoiced and/or deleted. In particular compare the development of /IJg/clusters in Northern German (NG) and in Standard German (SG) to the relative stability of /l)k/ clusters in these dialects. /I}g/ (NG) /fJg/ (SG) Ding sing. pl. sing. pl. "thing" /dll)g/ /dlt}ga/ /dll)g/ /diT)ga/ /dlt}k/ /dll)k/ /dlt}a/ /diT)a/ /dlt}/ /T)k/ (NG and SG) Fink sing. pl. "finch" /flr)k/ /flt}bn/ The /T)g/ sequences have undergone three changes :
o) /g/
---+
(2) /k/ - (3) /g/ - - -)
~
I ITJI _ # I /I)/ __#in SG, wherever /k/ < /g/
~
I
/kl
fiJI _fa/.
Consonant cluster reduction and final devoicing
261
These phenomena have been discussed by a number of investigators, most notably Kiparsky (1972), Hooper (1976), and Vennemann (1970, 1974). Kiparsky claims that the dialects in question have an underlying post-nasal /g/, but that through time German has added two ordered rules to its grammar: (i) a rule that devoices all final and pre-consonantal obstruents and (ii) a rule that deletes /g/ after a nasal. He accounts for the difference between NG and SG by hypothesizing that the rules were reordered in SG so that /g/ -deletion applies before devoicing (1972: pp. 209-210). Although this is a clear characterization of German phonology at different points in space and time, Hooper notes that "Rule reordering is a description of a particular linguistic change but, in itself, not an explanation" (1976: p. 92). Hooper, I think, is correct; it is not at all clear what would motivate a speaker to spontaneously reorder two rules in his grammar. Hooper, however, does not attempt to explain the changes that have occurred; rather, she argues against Kiparsky's claim that there is an underlying /g/ in both dialects of German. Hooper, who takes her analysis from Venneman (1974), proposes that NG has an underlying /k/ inserted by an "arbitrary" morphophonemic rule but that SG has neither a /g/ nor a /k/ in its underlying representation (1976: pp. 95, 97). Although her analysis is preferable to Kiparsky's in that she assumes that a speaker would be constrained from internalizing an underlying form that contains a segment which never appears phonetically (Vennemann's Strong Naturalness Condition), she still avoids the question of what caused the change in the first place. She claims that the two rules, devoicing and /g/-deletion, were simply "added" to the grammar of German (1976: p. 97). Vennemann, on the other hand, does "attempt an explanation" of the /g/-deletion phenomenon; he notes that fg/ is deleted after a nasal when the /g/ occurs before zero stress (1970 : p; 74). This solution, however, is incomplete in two respects. First, it does not deal with the de voicing of /g/ to /k/, and , second, it is simply a statement of the conditioning environment for /g/-deletion; it does not explain the relationship between /g/-deletion and zero stress. Since the generative analyses do not seem to shed much light on the actual mechanism of phonological change, it might be worthwhile to examine the German data in terms of ACs. The ACs relevant here are those for fmal post-vocalic stops (as in cat - cad), postnasal stops (as in can't- canned), and post-vocalic nasals (as in can).' It is generally agreed that stop release in fmal position is sufficient to discriminate between voiced and voiceless stops (Malecot 1958: p . 379; Wang 1967: p. 343). However, it is also known that stops in final position may be, and in fact usually are, unreleased (Francis, 1958: p. 73 : Chen & Wang, 1975 : p. 270; Umeda & Coket,.- 1975: p. 545). In the case of unreleased post-vocalic stops, the voice value is signalled by the manner in which the preceding vowel is terminated (Parker, 1974) 2 . That is, a post-vocalic voiceless stop is cued by abrupt termination of the preceding vowel and a post-vocalic voiced stop is signalled by gradual termination of the preceding vowel. "Termination" as used here is defined in terms of the period of vocal cord 1
The work on ACs cited here is primarily from English. However, since German and English are both Germanic languages and thus share much of their historical development, the principles governing the ACs for English stops and nasals will be assumed to hold for German. 2
1t is often maintained that preceding vowel length cues the voice value of a following stop. (See Parker, 1974: p. 212 for references.) However, historical evidence indicates that vowel length is not a stable cue. For example, differences in vowel length in Chinese were quickly reinterpreteo as distinctive pitch contours, and vowel length differences in Sanskrit and Vulgar Latin were superceded by qualitative differences in vowel height (Chen & Wang, 1975 : pp . 272-273). Moreover, Eilers (1977) finds that infants are able to discriminate between post-vocalic /d/ and /t/ even when the length of the preceding vowel is held constant. Such phenomena indicate that vowel length is not crucial for the perception of voicing in post-vocalic stops.
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vibration during the transition from vowel to stop. Before a voiced stop the period gradually lengthens; no such change occurs before a voiceless stop (Parker, 1974: p. 218). In fact, fmal post-vocalic voiceless stops in English are regularly produced with complete glottal closure (Umeda & Coker, 1975: p. 545), which causes abrupt terrilination of the preceding vowel. 3 Moreover, gradual vowel termination, unlike abrupt termination, is an ambiguous AC. A vowel in fmal position, as well as a vowel preceding a voiced stop, exhibits period lengthening. If a post-vocalic voiced stop is unreleased as in cued [kjud'] , it is often confused with a vowel-final utterance such as cue [kju] (Parker, 1974: p. 217). 4 The situation is even more complex with ACs for post-nasal stoRs. If a nasal is followed by a voiceless stop, the vowel becomes nasalized and the nasal segment drops out. That is, can't /kcent/, for example, becomes [kret] phonetically (Malecot, 1960: Parker, 1977a). Thus, a post-nasal voiceless stop has the same AC as a post-vocalic voiceless stop- abrupt termination of the preceding vowel; the only difference between such utterances is in the nasalization of the preceding vowel. On the other hand, the nasal preceding a voiced stop does not drop out phonetically; that is, canned /kcend/ becomes [krend] phonetically (Malecot, 1960 : Parker, 1977a). The AC for a post-nasal voiced stop, then, cannot be gradual vowel termination, since such a stop is not directly preceded by a vowel. Instead, a post-nasal voiced stop is cued only by its release; if it is not released, it is acoustically similar to an utterance without a stop. That is canned [krend'] is acoustically the same as can [kren') (Parker1977a: p. 102). The ACs for post-vocalic nasals in final position are not nearly as sensitive to context as are the ACs for fmal, post-vocalic and post-nasal stops. Nasal segments are signalled by a single bar of low frequency resonant energy and a complete lack of high frequency energy (Cole & Scott 1974: p. 353) . Thus, because of their vowel-like spectral qualities, nasals have stronger ACs than do stops, in final position (Chen & Wang, 1975: p. 270- 1). Two significant facts emerge from this discussion of ACs. Not only are ACs (especially those for stops) highly context-dependent, but also they vary in their relative strength and ambiguity. If we restrict our discussion to the ACs for final, unreleased 5 stops and nasals, we can rank these cues as follows. (Let V =vowel, N =nasal, and C =stop.) The cues for fmal voiced stops,.then, are weaker than those for final voiceless stops, which in turn are weaker than those for final nasals. (Here an ambiguous cue is assumed to be weaker than an unambiguous cue.) 3
Additional support for this cue is provided by the historical development of Chinese Chen & Wang (1975: p. 267) note that in the process of losing final post-vocalic voiceless stops, Chinese went through a stage where all the voiceless stops reduced to a glottal stop . This is clearly no accident. A postvocalic glottal stop per se forces abrupt termination of the preceding vowel. The vocal folds are brought together quickly by mechanical means rather than being allowed to come to rest by gradual obstruction of the airflow in the oral cavity (Parker, 1974: pp. 216-217). The fact that post-vocalic voiceless stops reduce to a glottal stop suggests that the AC for all of them is the same, abrupt termination of the preceding vowel. 4
There is historical evidence that just such 'confusability' causes change . For example, OE daeg 'day' comes from West Germanicdag /dag/ and thus originally ended in a voiced palatal stop [.t 1. (Here [.t 1 /g/ as a result of the fronting effect of the vowel (ae 1.) The fact that Mod .E. day has no final voiced stop can be explained as follows. If [ t 1 is released, a stop is clearly perceptible; if it is not released the gradual termination of the vowel may be perceived as a vowel (or in this case a glide). Thus, we have the following progression: /daeg/ - - - 4 (dae ----+ (dae .t7 ] - - 4 [daej I - - 4 (dej 1. (The change in vowel quality is irrelevant to this discussion.) 5 Since all of the segments under consideration may be unreleased, I will assume that this limiting case obtains throughout the discussion. It should be noted, however, that all final released stops and nasal have "stronger" ACs than their unreleased counterparts (Wang, 1967: p. 348).
<
;n
Consonant cluster reduction and final devoicing Strongest - VN
vc
- (can [kren1 ] -(cat [ka£]
263
- ACs present throughout vowel and closure -one unambiguous cue, abrupt vowel termination
[-vee] VNC
-(can't
[~t']
- same as above
[-vee]
vc
- (cad [ka:d']
-one ambiguous cue, gradual vowel termination
[+vee] Weakest
VNC
-(canned [krend7 ] - no AC
[+vee] Moreover, if we view phonological change as a function of ACs, it is reasonable to expect that those segments with relatively "weak" ACs will be most likely to undergo change; what's more, we would expect change to proceed from weak to strong. That is, we might expect canned to become can't and can't to become can, but not vice versa. The directionality of change is, however, only part of the picture. It is also necessary to determine what causes the appearance of acoustically unstable segments in the first place. For the purposes of illustration, let's assume the simplest, most "natural" type of syllable structure- cl vI c2 v2 c3 v3' (see Shane, 1973: pp. 52-3). When stress becomes fixed on the first syllable (as has occurred in all the Germanic languages), the unstressed vowels are reduced and eventually lost; that is, cl v 1c2 v2c3 v3~ cl VI c2 ac3 a~ cl vI c2 ac3~ cl vI c2 c3. Since, as we have seen, the ACs for stops are carried by neighboring vowels, then loss of the final [a] removes half of the potential cues for C3 and loss of the preceding [a] obliterates the remaining cues for C3 as well as half the cues for C2 . Thus, after the unstressed vowels are reduced and deleted, tha ranking of C1 - C3 in terms of the relative strength of their ACs is C1 -strongest, C2 -weaker, and C3 - weakest. This provides us with a complete (if somewhat oversimplified) model of phonological change: fixed stress causes vowel reduction and deletion, which in tum causes weakening of ACs for the neighboring consonants. Those consonants with weak ACs are replaced by segments with stronger ACs. Let's now return to the problem of explaining the three changes that have occurred in German. The first change is the devoicing of post-nasal stops in fmal position, specifically /g/ ~ /k/ / /ql-- ~ We must begin by putting this phenomenon into its historical context. First, the proto-forms for members of theDinge-Dinge and Fink-Finken paradigms originally had a full vowel following the nasal + stop clusters; we may assume this, because in IndoEuropean, nouns typically ended in a non-reduced vowel or carried an inflectional suffixbeginning with such a vowel (Misra, 1968: pp. 52-60). The reconstructed forms then are /dlTjgV/-/diqgV/ and /flqkV/-/fiTJkVn/. (The exact quality of the vowel is unimportant). Second, these vowels eventually reduced to ral, due to the fixed stress on the first syllable of native words. (See MacCarthy, 1975: p. 10). Thus, the proto-forms reduced to /ding e//dlrpy,f and /flrJka/-/fii)kan/, respectively . Third, the Ac for the /g/ in the ding paradigm, but not that for the /k/ in the fink paradigm, is carried by the [a] . Stop release in fmal position constitutes an incipient centralized vowel; that is, [C-] = [Ca] (Parker, 1977a: p. 103). Therefore, since the AC for a post-nasal voiced stop is release, and since release = [a], then the AC for the /g/ in /dlqga/ must be [a]. Fourth, eventually the final [a] in the singular was lost. 6 This created an acoustically unstable situation, since it in essence deprived all final post-nasal voiced stops of their AC. 7 6
Loss of final [a] is a widespread phenomenon.lt has occurred in all the Germanic languages (Lehmann, (1962: p. 161; Hooper, 1976: p. 102) and Galla-Romance (Chen & Wang, 1975: p. 269; Hooper, 1976: p. 104-5). 7
The effect was considerable. Stampe notes that loss ofword.final [aj 's in German caused "thousands" of voiced stops to show up in final position (1969: 453).
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Three possibilities existed to compensate for this unstable situation. (1) The stop could simply have been released. However, this apparently was not a viable alternative since release would contradict the general loss of fmal [a] . That is, since [C a] = [C) .loss of final [a] necessitates nonrelease of the stop. Moreover, releasing the stop would cause the singular and plural forms to fall together. That is, since [dh)g-) and [dlr)ga] are similar acoustically, the singular/plural distinction would have been obliterated for all nouns of the Ding-Dinge paradigm. 8 (2) The stop could have been lost. That is, [dlrjg ] might have become /dii]/. Why it did not is somewhat unclear. However, we have to assume that although simple loss of /g/ was a viable alternative, it simply did not occur. It is worth noting that in English, where the same phonetic conditions obtained, voiced velar and labial stops were lost after nasals . For example,in Mod. E. we have climb /klaim/
is worth noting that German apparently did prefer the 'release' solution in the Bunde-Bundes paradigm in dialects of NG, where final voiceless stops have been revoiced as in [bUnd- ] - (bUnd:ls] ,(see Kiparsky, 1968: p. 177). Note, however, that release of the /d/ in final position does not cause the singular and plural to fall together, since this paradigm has fmalf;-,s/ rathen than f;-,•f in the plural.
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variably by speakers of languages such as Tamil, Japanese, and Italian (pers. comm.) The explanation for this phenomenon is similar to that for the German data. Post-vocalic voiced stops have two cues: release and gradual termination of the preceding vowel. The pronunciation [d:Jg:l] represents dependence on the release cue. When unreleased, however; a post-vocalic voiced stop is not only reduced to a single cue, gradual vowel termination, but an ambiguous cue at that. Thus, for a speaker to preserve the stop without having to release it and without having to depend on an ambiguous cue, he may signal it unambiguously by abrupt termination of the preceding vowel. This, of course, entails devoicing the stop. course, entails devoicing the stop. Note, in addition , that the widespread tendency for languages to devoice fmal stops (King, 1976 : p. 29; Stampe. 1969 : p. 445; Marcari, in press) can be accounted for by this analysis. A final unreleased post-vocalic voiced stop has one, ambiguous cue-gradual vowel termination; a voiceless stop in the same phonetic context has one unambiguous cue-abrupt vowel termination. Thus, devoicing a final. post-vocalic stop in essence "strengthens" its AC. Let's now consider the second phonological change illustrated by the German data- the loss of post-nasal voiceless stops in fmal position in SG . In particular, post-nasal /k/ was deleted in final position sometime after the Middle High German period, changing ding from /di!Jk/ to /dlq/ . The primary force effecting the loss of /k/ is the relative weakness of abrupt vowel termination .as the AC for post-vocalic stops. (Recall that /dlqk/ reduces to [dik] phonetically). We know that unreleased stops are harder to perceive than nasals in the same articulatory position (Chen & Wang, 1975 : pp. 270-271). Thus, the AC for the fmal segment in [dik7 ) is weaker than that for the fmal segment in [dl'ij 7 ], We may hypothesize that even though the listener was exposed to [dlk 7 ] , he assigned the utterance the structure [diiJ 7 ] because the cue for the nasal is stronger than that for the stop. The speaker then internalized the underlying form /dlf)/. Still it remains to be shown why the /k/ was lost in the ding paradigm but not in the fink paradigm . That is , /k/ was lost in final position after a nasal, but only where /k/ was historically derived from /g/. Even though we have to assume that both /k/'s were acoustically identical, the cause for such "selective" change may be found in paradigm pressure. That is, a /k/ occurred in the plural of the fink paradigm {/flqk:ln/) but not in that of the ding paradigm {/dhp/). Although the ACs for both /k/s were weak, the /k/ in fink could be reconstructed on the basis of the /k/ in fznken; whereas the /k/ in ding was lost since there was no velar stop in dinge to serve as a model. German provides other examples of similar phenomena. For example, hintbere in Old High German shows up as Himbere in SG. The /t/ is unreleased because 7it is followed by another obstruent, (see Wang, 1967: p. 343). Therefore, the only AC for [t ] is abrupt vowel termination. Because of the weakness of the cue, the (t 7 ] was apparently not perceived by new speakers and thus was not internalized as part of the base form of hintbere. In the absence of the /t/, the nasal was free to assimilate to the point of articulation of the /b/ . . In addition, Bithell notes ,.''Omission of the [t] in und is very common in word groups in conversation: kurz und gut (kurts un gu :t]" {1952 : p. 197). The point of interest here is not the accuracy of Bithell's observation, but rather what it reveals about the relative strength of abrupt vowel termination as an AC . We know that und does have an underlying stop. It occurs in slow careful speech and before vowels. Thus, it may be more accurate to say that even though German speakers do produce the final /t/ in und, listeners typically do not perceive it because of the weakness of its AC when 11nreleased, as it is before a consonant. Moreover, the loss of final, unreleased voiceless stops is not restricted to German. This phenomenon is, in fact, fairly widespread . For instance, as mentioned above, Chen and Wang discuss the different stages of the loss of such stops in different dialects of Chinese, (see footnote 3). This can be explained as a function of the relative weakness of abrupt vowel termination as an AC. Final voiceless stops were unreleased in Chinese, and because of the relative weakness of the single cue, the stops were no longer perceived and were eventually lost.
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Let us now consider the third and fmal change illustrated by the German data: the loss of voiced stops between a nasal and a following vowel. Such a change occurred in the plural of dinge, where /diqga/ became /dlrp/. It will be noted, however, that the analysis of the other two changes in German would predict that loss of post-nasal /g/ before Jaj should NOT occur, since the AC for the stop is release and release = [a] . Nevertheless, there are extenuating circumstances that must be considered in order to bring this phenomenon in line with the analysis of the other two changes. First, we may assume that the /g/ in dinge was syllable initial in Proto-Germanic, since it occurred before a full vowel. Venneman notes that "In Ingrid, Anglia, Anglist, as well as in Tango [where /g/ precedes a full vowel], the /g/ belongs in the following syllable, while [word fmally and before a consonant or I a/] it is more closely allied with the preceding syllable as a consequence of zero stress" (1970: p. 74). That is, post-nasal /g/ preceding a full vowel constitutes the onset of that syllable, and elsewhere it forms the coda of the preceding syllable . Thus, we can assume that the ProtoGermanic form of Dinge was /diq$gV/. 9 ($=syllable boundary). Second, since syllabicity is apparently dependent on stress, we may assume that a change in stress can effect a change in syllabicity. When a vowel becomes unstressed, the preceding consonant may become the coda of the preceding syllable. For example, compare the syllable structure of the following pairs of words: economics /ikaSriamlks/, economy /ikan$ami/ and psychology /sai$kalaji/, psychological /salk$ alajekal/. (Note that economics */i.kan$amlks/ and psychology* /salk$:HaYi/ are both unacceptable since the consonants /n/ and /k/ respectively are analyzed as part of the preceding syllable when the following vowels are stressed). The change in syllabicity becomes clear when we consider the shortened forms of these words: econ /ikan/ and psych /salk/. In these examples, it is obvious that the /n/ and the /k/ have been reanalyzed as part of the preceding syllables. Moreover, compare sentential and sentence. In the former there is a clear syllable boundary between the first /n/ and the following /t/: [sln$tfncal]. On the other hand, in sentence the /t/ may reduce to [7], and we get [si?$?ts]. We can deduce that the syllable boundary comes between [?] and [n], since we have already seen that [?] constitutes abrupt termination of a preceding vowel, (see footnote 3). Because a vowel and its termination are inseparable, the glottal stop must be part of the same syllable as the preceding vowel. Thus, from this type of data we can conclude that when the fmal vowel in dinge became unstressed and reduced to [a] , this could cause the syllable boundary to shift so that /dlr).$gV/ became /diqg$a/. (For a detailed discussion of the effects of stress on syllabicity see Parker, in press.) lengthened before /mb, nd, ld, rd, r'J/ except when a third consonant followed (Pyles, 1971 pp. 163-164). Therefore, in OE we have cild /clld/ and cildren /Clldr!n/, but in Mod. E. we have child and children. The vowel in the singular has been lengthened and raised. The fact that this change has occurred in the singular but not in the plural must be a function of syllabicity, since that is the only difference between the environments of the vowels in the two words. In cild the /1/ and /d/ are in the same syllable (/clld$/) but in cildren they may be in different syllables (/W$dr€n/). Thus, lengthening apparently operated in vowels preceding preceding /ld'$/ but not on those before /l$d/. 10 9
Actually, the /f)/ may not have been velarized in the protoform, since IndoEuropean is not known to have had /n/ (Lehmann, 1955: pp. 7 -8). /n/ is probably the result of assimilation to the place of articulation of the following velar; however, this need not concern us here. 10
It is worth mentioning that this same data provides evidence that syllabicity changes back and forth through time . Vowel lengthening before the consonant clusters mentioned above was unstable. Vowels in these environments lengthened and then shortened in some words. For example, compare wind (noun) and friend, in which the vowel has reshortened, to wind (verb) and fiend, in which the vowel has remained long (Pyles, 1971: pp. 163-164).
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Finally, the AC for a syllable-final post-nasal voiced stop seems to be the same as that for one in final position, namely release. This is because the same articulatory and acoustic conditions obtain for both. Note that if a syllable-fmal post-nasal voiced stop is released, an intrusive [ "] results. For example [af)g-$a] becomes something like [al)g"a] phonetically. On the other hand, if the stop is not released, it,just like its word-fmal counterpart, has no AC and thus is not perceptible . That is, for instance, [aiJg7 $a] reduces to [an!J$a]. which appears as [aiJa] phonetically. Thus, a syllable-final post-nasal voiced stop is in much the same sort of acoustically unstable position that a word fmal post-nasal voiced stop is. We now have enough information to suggest an explanation for the loss of /g/ in Dinge. The change can be reconstructed as follows: [di!J$gV] -proto-form [dlrj$g"] -vowel reduction [di!Jg$"] -loss of stress causes resyllabification [dh}g' a] - fg/ is unreleased in syllable-final position: [g 7 ] has no AC after a nasal - [g7 ] is not perceptible, since it has no AC [dlt)0"] -fg/ is not stored in the grammars of n:ew speakers, since they do not [dbp] perceive it. This account of the Joss of /g/ in Dinge is applicable to a variety of similar changes in a number of languages. For example, the same phenomenon occurs in some dialects of English as well as in rapid speech, as in finger [fiiJ"r] , longer [biJ"r] , and strongest [str:>IJ"St] . Moreover, Bithell notes that "In Plattdeutsch these assimilations are the rule : go/len= golden, . . . finnen = finden. We find this assimilation in popular orthography (which correctly reproduces the sound heard): in nachtschafener Zeit (for -ender)" (1952: p. 193). These so-called "assimilations" can be explained exactly the same way as the loss of fgf in dinge : the voiced stop is unreleased in syllable-fmal position, and an unreleased voiced stop has no AC after a nasal or a lateral. Note, in this same vein, the scarcity of fmal /lb/ and /lg/ clusters in English; I can think of only bulb. On the other hand, final /lp/ and /lk/ clusters are common, for example, gulp, pulp, help, kelp, scalp, and hulk, sulk, milk, silk, bulk, etc. (The common occurrence of final /ld/ clusters results from morphological pressure. /d/ is one of two productive past tense inflections in English, and thus must be retained even in what are relatively unstable acoustic environments (Parker 1977a: p. 104).) Furthermore , this analysis accounts for some related phenomena. For example, it helps explain why in English we can delete /g/ in English [IIJlls] but not in Angola * [aei)ol ;i] . In English the /g/ precedes an unstressed segment and thus may be analyzed as syllable-fmal; in Angola it precedes a stressed segment and therefore must be analyzed as syllable-initial. In the former the /g/ must be unreleased . In addition, the explanation proposed here accounts for Vennemann's observation that "Strictly speaking, there never was an historical process of g-deletion. The segments /g/ and /b/ in the clusters /J}g/ and /mb/ were assimilatorily nasalized; the resulting /mm/ and /rm/ were later degerninated ... " (1974 : p. 214). The unreleased /g/ in syllable fmal [1Jg 7 ] clusters, although not perceptible as a stop, was perceptible as a lengthening of the nasal. That is, [l)g 7 ] is phonetically similar to [r)l)] . The 'long' nasal was shortened because length is not distinctive in German consonants. Finally, this analysis accounts for the retention of post-nasal /k/ in finken as well as the loss of the post-nasal /g/ in dinge . Even if resyllabification took place within the /k/ paradigm, it would not obliterate the AC for /k/ since before a voiceless stop the nasal drops out and the cue for the stop is carried by the preceding vowel. That'is. /diry$gV/ becomes [dlr)g7 $"] , but /flr)$kVn/ becomes /fik'$;}n/. In summary, the analysis presented here is more than simply an attempt to account for three changes in German phonology. It is rather an effort to show, fust, that phonological change cannot be fully understood without reference to ACs. Such cues are contextdependent just as phonological change is, and ACs are the elements of the signal by means
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of which speakers· recover phonological segments. Second, ACs form part of a general paradigm of ·phonological change. Fixed stress causes vowel reduction and eventual deletion. Vowel loss in turn introduces consonants (in particular stops) into acoustically unstable positions by eliminating the environments that carry their cues. Third, the direction of phonological change is a function of the relative strength of the Acs for the segment involved. Segments with relatively weak ACs tend to be transformed into segments with stronger AC's. In particular, the cues for final voiced stops are weaker than those for fmal voiceless stops, which in tum are weaker than those for fmal nasals . The German data discussed here exemplify this general progression : /dlf)g/ --+ /dlr)k/ --+ /dlf)/. References Andersen, H. (1973). Abductive and deductive change. Language 49,765 - 793 . Bithell, J . (1952). German Pronunciation and Phonology. London: Metheun & Co . Chen, M. Y. & Wang, S. Y. (1975) . Sound change :actuation and implementation. Language 51 , 255-281. Cole, R. & Scott, B. (1974) . Toward a theory of speech perception. Psychological Review 81, 348 - 374 . Eilers, R . E. (1977). Context-5ensitive perception of naturally produced stop and fricative consonants by infants. Journal of the Acoustical Society of America 61, 1321 - 1336. Fodor, J., Bever, T ., & Garrett, M. (1974). The Psychology of Language . New York : McGraw-Hill. Francis, W. N. (1958) . The Structure of American English. New York : Ronald Press. Hooper, J. (1976) . An Introduction to Natural Generative Phonology. New York: Academic Press. King, R . D. (1976) . The History of Final Devoicing in Yiddish . Bloomington : Indiana University Linguistics Club. Kiparsky, P. (1968). Linguistic universals and linguistic change. Universals in LinKUistic Theory. Back, E. & Harms, R. (Eds.) . New York: Holt , Rinehart & Winston, 171-202 New York : Holt, Rinehart & Winston. KiparSky, P. (1972). Explanation in phonology. In On the Goals of Linguistic Theory, (Peters, S. Ed.), pp . 189-227. Englewood Cliffs, New Jersey: Prentice-Hall. Lehmann, W. P. (1955). Proto-Indo-European Phonology. Austin: University of Texas Press and the Linguistic Society of America . Lehmann, W. P. (1962). Historical Linguistics. New York: Holt, Rinehart & Winston. Liberman, A. M., Cooper, F. S., Shankweiler, D. P, & Studdert-Kennedy, M. (1967). Perception of the speech code . Psychological Review 74,431 - 461. Macari, N. Some psychophysical evidence for natural phonological processes. Journal of Phonetics. (In press). MacCarthy, P. (1975). The Pronunciation of German . London: Oxford University Press. Malecot, A. (1958) . The role of releases in the identification of released final stops. Language .34, 370-380. Malecot , A. (1960). Vowel nasality as a distinctive feature in American English. Language 36, 222 - 229. Misra, S. S·;·(i 968) . A ·Comparative Grammar of Sanskrit, Greek, and Hittite. Calcutta: The World Press . Parker, F. (1974). The coarticulation of vowels and stop consonants. Journal of Phonetics 2, 211 - 221 . Parker, F. (1977a) . Perceptual cues and phonological change . Journal of Phonetics 5, 97 - 105. Parker, F . (1977b) . Distinctive features and acoustic cues: Journal of the Acoustical Society of America Parker, F. (in press). Resyllabification and phonological change. Journal of Phonetics. Pyles, T . (1971) . The Origins and Development of the English Language. New York : Harcourt, Brace, Jovanovich. Schane, S. (1973) . Generative Phonology. Englewood Cliffs, New Jersey: Prentice-Hall. Stampe, D. (1969) . The acquisition of phonetic representation. Chicago Linguistic Society 5, 443 - 454. Umeda, N. & Coker, C. H. (1975). Subphonemic details in American English. In Auditory Analysis and Perception of Speech. (Fant, G. & Tatham, M., Eds). Pp. 539-564. New York : Academic Press. Vennemann,-T. (1970). The German velar nasal: a case for abstract phonology. Phonetica 22, 65-81 . Vennemann, T . (1974). Phonological concreteness in natural generative grammar. In Towards Tommorrow's Linguistics. (Shuy, R. & Bailey, C., Eds). Pp. 202-219 . Washington: Georgetown University Press. Wang, S. Y. (1967). Tr-ansition and release as perceptual cues for final plosives. In Reading in Acoustic Phonetics. (Lehiste; 1., Ed .). Pp. 343-350. Cambridge, Massachusetts : MIT Press.