5.3 T HE VOWEL CHANGE IN THE FRAMEWORK OF FUL
5.3.3 The effect of the NZE vowel shift on synchronic alternations
English has few synchronic vowel alternations, among them umlaut in a handful of nouns (e.g.
foot~feet) and ablaut in irregular verbs (e.g. swim~swam). Both alternations primarily involve place of articulation oppositions (i.e. dorsal versus coronal vowels or vice versa). On the other hand, there exist height alternations co-occurring with the widely discussed English trisyllabic shortening (TSS, e.g.
sincere~sincerity, c.f. Lahiri and Fikkert, 1999; Myers, 1987), but also in medial laxing (e.g.
preside~president, c.f. Lahiri and Fikkert, 1999). These alternations make up an excellent data set for examining the NZE short front vowel shift. In particular, TSS describes the process of shortening the vowel in a stressed syllable if two syllables follow (i.e. [i] in sincere changes to [] in sincerity). Medial laxing, on the other hand, results from the resolution of a stress clash via the shortening of the tense and stressed vowel (i.e. [ai] in preside changes to [] in president). The quantity alternations involve a concomitant quality (height) alternation of the respective vowels, as shown in the following examples for RP TSS:
(27) vain ~ vanity V ~ V [ei] ~ [æ]
(28) obscene ~ obscenity V ~ V [i] ~ []
In (27), the diphthong [ei] of the adjective vain with its non-low on-glide alternates with its low counterpart [æ] in the noun vanity. Similarly, the long high vowel [i] in the adjective obscene in (28) alternates with the non-high vowel [] in obscenity.
In NZE, however, one would expect the height contrast between the stressed vowel in vain versus vanity and obscene versus obscenity to be lacking, since both [æ] and [] have been raised. This is in fact what one finds. There is neither a height contrast between the stressed vowel in vain and vanity nor
in obscene and obscenity. Note that the vowel quality differs nevertheless. The short vowel in the nominal derivations has the feature retracted tongue root (RTR), while the long vowel (or diphthong) in the adjectives involves the feature advanced tongue root (ATR) reflecting the normal shortening. Note that the long [i] in obscene is not affected by the vowel change, while the short [] in –ity is lowered and centralised. This can be seen in NZE transcriptions (e.g. in Orsman and Wattie, 2003). Table 51 compares NZE with RP regarding the concomitant vowel quality change of TSS.
Table 51: TSS with and without vowel height alternations in RP and NZE.
ORTHO
As can be seen above (Table 51), TSS in NZE does not involve a height opposition. The stressed vowels in vain and vanity are similarly underspecified for height, and equivalently, the stressed vowels in both obscene and obscenity are high. This observation is in accordance with Bauer, 1986; 1995. He shows that the pronunciation of the stressed vowel in explanatory is the same as the pronunciation of the stressed vowel in explain (i.e. [ei] in both cases). Bauer states that „the pronunciation of the base of a complex word is retained as it would if that base were pronounced in isolation, and ignoring any morphophonemic changes which take place in other varieties of English [⁄] it does seem that spelling is not the primary motivation for such variants [⁄]‰ (Bauer, 1995:322)70.
Bauer is right. The primary motivation for such variants (compared to the canonical RP pronunciations) does not have to do with orthography, but lies in the short front vowel shift of NZE.
This is further evidence for the claim that the change in NZE is phonemic rather than phonetic.
Evidence from behavioural experiments for such a phonemic change is provided in the following section.
70 Note that in this example, the vowel in the derived noun is not really shortened. Nevertheless, there is no height difference between the vowel in the verb explain and in the adjective explanatory. An alternative explanation could be that the vowel in the noun is retained via surface analogy, counter-acting the so-called spelling rule alternation (Eddington, 2001) accounting for morphemic relatives such as sane~sanity. A shortcoming of Eddingtons study, however, is the complete neglect of English TSS applicable to the example above. Besides, I encountered many instances of trisyllabic shortening with quality but not with height difference in NZE.
- 189 -
5.4 Behavioural evidence for non-low <a>
71in NZE
5.4.1 Assumptions
With respect to the NZE vowel change, the so-called indirect priming experiment has been applied in order to investigate the diphthong merger (Warren and Hay, 2006; Warren et al., to appear; Warren et al., 2004). This merger leads to asymmetries in perception, for the following reasons. If a NZE speaker hears beer, for instance, he ought to access both the meaning of beer and the meaning of bear, since the vowel in bear raised to [i]. However, if the same speaker hears bear (with a distinct diphthong [e]), only the meaning of bear ought to be activated. Warren and his colleagues (Warren and Hay, 2006;
Warren et al., to appear; Warren et al., 2004) investigated this case, using the indirect semantic repetition priming design with an auditory lexical decision task. In this task, subjects heard pseudo-randomised lists of words and nonwords and had to press the appropriate word/nonword button on a reaction-time measurement device. Test pairs consisted of words containing [e] and [i] words (primes), while the targets were semantic relatives of the primes (i.e. drink or animal). The notion „indirect‰ semantic priming refers to the condition in which bear is the prime and drink the target. If the lexical decision on the word drink is sped up in this condition, bear has obviously co-activated beer and therefore indirectly activated drink, which leads to the priming effect.
Warren et al. found that beer primed drink better than beer primed animal and bear primed animal better than bear primed drink. However, beer also primed animal, but bear did not prime drink.
Furthermore, the lexical decision time on [i] words was significantly longer than on [e] words. This was attributed to the fact that only the former words were homophonous while the latter were not, i.e.
the direction of the merging towards [i] was confirmed by the data.
Can the same rationale be applied to an indirect semantic priming experiment with words of which the stem vowel is affected by the NZE vowel shift? In particular, can a word like bat be successfully activated by bit or bet in NZE and would that contrast with AE? In terms of an indirect semantic priming experiment, can bet and bit prime the semantic relative of bat, i.e. club, in NZE (experiment 1)?
And likewise, can bet and bit prime the semantic relative of bat in AE (experiment 2)?
FUL makes specific predictions for these cases. The crucial assumption is that if the vowel in bat is in fact non-low (i.e. mid or not specified for height, respectively), a phonetically high vowel (such as in NZE bet) or a non-high vowel (such as in NZE bit) should be a nomismatch for bat. This is illustrated in Table 52.
With respect of place of articulation, all three primes have a stem vowel which does not mismatch with the lexical representation of <a> being underspecified for coronality. In general, FUL assumes that coronality is not represented in the mental lexicon (cf. chapter 1).
Regarding vowel height, the following predictions hold: In condition 1, bit pre-activates the semantic relative of bat via bat, which has no lexical height specification. The features from the signal
71 This orthographic transcription refers to the vowel in bat. For the reminder of this chapter, orthographic rather than phonetic transcriptions are used in order to compare the different pronunciations between NZE and AE which go back to the same (orthographic) words.
and the features in the mental lexicon do not mismatch. Thus, the lexical decision time of the target will be sped up and full priming is obtained.
Table 52: Priming predictions for an indirect priming design on NZE short front vowels.
FEATURES OF PRIMES
(SIGNAL)
FEATURES OF BAT
(LEXICON) CON
-DITION
PRIME
PLACE HEIGHT
TARGET
PLACE HEIGHT
MATCH PRIMING
(1) bit [COR] [LAB]
[]72 club [] [] no mismatch yes
(2) bet [COR] [HIGH] club [] [] no mismatch yes
(3) bat [COR] [] club [] [] no mismatch yes
In condition 2, [HIGH] from the signal does not mismatch with bat, since its root vowel has no height information in the lexicon. Therefore, priming is expected in this condition as well.
In condition 3, a nomismatch occurs, since the vowel height is neither specified in the signal nor in the lexicon. Hence, both bit (phonetically not specified for height) and bet (phonetically high) should prime the semantic relative of bat in comparison to a control condition, in which an unrelated item precedes the semantic relative of bat. In fact, both bit and bet ought to prime the semantic relative of bat to a similar degree.
An exemplar-based model, in contrast, would predict that bet, being acoustically most distant to bat in NZE, should be the least likely variants of bat. Therefore, bet ought to yield the least amount of priming. Altogether, the interaction of exemplar-representations and pre-lexical biasing should lead to gradual priming effects, in that bet primes club least and bat primes club most.
FUL predicts no significant priming differences among the three conditions. However, if the same stimuli were presented to speakers which have a lexically low <a>, a high vowel in the signal should mismatch with low <a> in the lexicon. Thus, for varieties of English with a low <a> (e.g. American English with a three-way height distinction for the short front vowels), the priming expectations in FUL would differ as summarised below (Table 53).
As for place of articulation, the assumptions are similar than for the NZE listeners, except that if labiality is extracted from the prime (condition 1), this feature is incompatible with [LOW] in the mental lexicon. This constellation is somewhat different than a feature mismatch within one domain (e.g.
height or place), but should nevertheless result in reduced or no priming.
72 Note that it would be theoretically possible to invoke the extraction of the feature [MID] once the F1 frequency is within a certain range. However, this feature would never be contrastive in the phonology and furthermore would not alter the mismatching relations since it would be compatible with both [HIGH] and [LOW].
- 191 - The incompatibility emerges from the trend that American English does not have rounded (labial) low vowels (Labov, 2005; Wells, 1982b), i.e. American English vowels are either low or labial, but not both labial and low. Yet even if there were low labial vowels, they would be back (i.e. dorsal, []).
Hence, one could claim that the combination [LAB][COR] is inherently incompatible with [LOW] and therefore counts as a mismatch73. Altogether, then, bit is predicted not to co-activate bat and therefore, the semantically related target to bat will not show a lexical decision time advantage, i.e. there is no priming.
Table 53: Priming predictions for an indirect semantic priming study with a low [æ].
FEATURES OF PRIMES
(SIGNAL)
FEATURES OF BAT
(LEXICON) CON
-DITION
PRIME
PLACE HEIGHT
TARGET
PLACE HEIGHT
MATCH PRIMING
(1) bit [COR]
[LAB]
[ ] club [] [LOW] mismatch no
(2) bet [COR] [HIGH] club [] [LOW] mismatch no
(3) bat [COR] [ ] club [] [LOW] no mismatch yes
In condition 2, there is a mismatch in the height dimension. The feature [HIGH] from the (NZE pronounced) prime bet contrasts with [LOW] in the lexical specification of the vowel in bat. No priming is expected in this condition.
Lastly, condition 3 should behave parallel to condition 3 for NZE listeners. If no height information is extracted from the prime vowel, there is no mismatch with respect to the lexical vowel specification. Hence, full priming is expected.
The predictions of an exemplar-based model would be similar as before. If distances in vowel realisations would affect the priming pattern, then the furthest vowel (i.e. [] in bet) should lead to the least amount priming. in this case. On the other hand, if priming would be based on the probability that either bit or bet would be a possible realisation of bat, it should display the same gradualism;
namely, bet should be the worst prime.
Note that if NZE and AE speakers would have the same short front vowel phonemes, NZE and American English listeners ought to show the same priming patterns. If <a> is low in both NZE and American English, bet and bit should not prime club, independent of the subjectÊs dialect. If, on the
73 Note that it might also be possible that AE listeners still extract [HIGH] from the coronal rounded vowel [] in which case there would be a mismatch in the height dimension with regard to the coronal unrounded low vowel [æ] in bat.
other hand, <a> is non-low in NZE and American English, bet and bit should prime club in both subject groups.
The predictions of FUL contrast with the latter view as well as with the expectations of exemplar-based models. They are summarised below and tested in an indirect semantic priming experiment with NZE listeners (experiment 1) and with AE listeners (experiment 2):
- The lexical representation of <a> is feature-based and highly abstract. Primes with a nomismatch relation of their vowel to <a> similarly facilitate the recognition of the semantic relatives of <a>-words.
- The lexical representation of <a> differs between NZE and AE which leads to differential priming patterns between the two subject groups.
5.4.2 Experiment 1: Indirect semantic priming with NZE listeners
5.4.2.1 Experimental design & pre-analyses
5.4.2.1.1 Material
16 triplets of English minimal pairs (e.g. bat–bet–bit) were selected as prime items. Each of the 48 test primes was a monosyllabic noun with a short vowel, conforming to the syllable structures CVC, CCVC, CVCC or CCVCC.
The targets were selected as semantic relatives of the test-primes containing the root vowel [æ], (e.g.
club for bat). Semantically rather than associatively related words were used, for two reasons: First, only semantically related words can actually tap into the meaning of the corresponding prime (Perea and Rosa, 2002). The nature of the indirect semantic priming design crucially hinges on semantic activation, rather than on associative (co)-activation. Furthermore, Perea and Rosa (2002:188) showed that in the time course of a lexical decision task, purely semantic relations decay faster than associative or mixed relations. That is, by using only semantically related targets, priming between test-pairs or test-pairs and fillers can be kept to minimum, if it is not avoided altogether.
The semantically related targets were chosen according to WebsterÊs dictionary of synonyms (Gove, 1968) and verified by WordNet (Miller, 2003). For the majority of primes containing <a>, the semantic relative was a (near)-synonym. No semantic relative of the <a>-primes had an associative or semantic relation to the <e>- and <i>-words of the same triplet, i.e. the target for bat was club and had no (obvious) relation to bet or bit. Otherwise, one could counter that bit may have facilitated the recognition of club by virtue of a semantic or associative connection between the two words.
Semantically related and unrelated word pairs were tested in an offline judgement study. 8 subjects (4 male) from a New Zealand English origin (mean age 25) had to rate the similarity in meaning between the two words in either a semantically related or in a control pair condition. Similarity ratings were given on a scale from 1 (very similar) to 5 (very different).
- 193 - Results. The ANOVA with JUDGEMENT as dependent variable used the independent variables
SUBJECT (as random factor), ITEM (related to the test pair) and RELATION (semantic, control). The factor
RELATION showed a strong effect (F[1,203]=691.01, p<0.001), indicating that subjects judged the semantically related items as more similar than the unrelated items (median 2 for related, median 5 for unrelated pairs).
Targets were also approximately matched to the frequency of their primes (48 per million [targets]
vs. 49 per million [primes], based on Cobuild Spoken Word Frequency, taken from CELEX (Baayen et al., 1993))74.
The experimental design involved three test conditions and one control condition. The appropriate prime occurred in the direct semantic condition (batÆclub), the inappropriate primes occurred in the indirect semantic conditions (betÆclub; bitÆclub) and the unrelated prime was used in the control condition (campÆclub).
All four conditions were distributed over four subject groups in a Latin Square design, such that group 1 had the appropriate (baseline) prime for club, group 2 the inappropriate <e>-prime, group 3 the
<i>-prime and group 4 the unrelated (control) prime. For the next test target, group 1 had the inappropriate <e>-prime and group 2 the <i>-prime etc.
Between prime-target pairs, word and nonword fillers were included. A short script in PASCAL ensured a pseudo-randomised distribution of 5-8 intervening fillers (3-4 prime-target pairs) and also determined the necessary number of fillers, which was 104. 68 of these fillers were nonwords. Primes were always words. The total number of items per group was 136. There were as many words as nonwords. Nonwords were derived from existing English monosyllabic nouns by changing one or more segments. All nonwords conformed to the English phonology and the CV-structure of the test items and were cross-checked by a native NZE speaker for their validity. The experimental items were read by a native speaker of NZE with phonetic training. The recording was done with a Sony Stereo microphone (ECMMS957) and stored on a DAT-tape. Subsequently, the material was digitised with the sound editing application Cool Edit Pro (Hain, 2003) with a sampling rate of 44.1 kHz (16 bit, mono). The cutting was done at zero-crossings.
5.4.2.1.2 Acoustic analysis of test stimuli
Prior to the acoustic analysis, the experimental stimuli were down-sampled to 11 kHz using Cool Edit Pro (Hain, 2003). Formant values (F1, F2, F3; cf. Table 54) were calculated using KAYÊs Multi-Speech (KAY, 2002). They stemmed from a LPC analysis at the midpoint of each vowel. The analysis involved a (full) Hanning-window with a frame length of 20 ms. The filter order was 12, using the auto-correlation method. Pre-emphasis was set to 0.9.
In a subsequent ANOVA with the factors ITEM (nested under VOWEL), FORMANT (F1, F2, F3),
VOWEL (<i>, <e>, <a>), and the interaction term VOWEL X FORMANT,the factor FORMANT was significant (F[2,40]=1926.23, p<0.001) as well as the factor VOWEL (F[3,40]=19.83, p<0.001). The interaction of
FORMANTXVOWEL was significant, too (FORMANT X VOWEL: F[2,40]=16.79, p<0.001). For the purpose of
74 A comparison of the Cobuild Spoken Word Frequency with both the Wellington Corpus of Spoken New Zealand English and the Canterbury Corpus revealed approximately the same frequency distribution for the test stimuli.
this study, it was crucial to determine the differences in the perceived vowel height as indicated by the F1 values75 across the three vowels. Therefore, a planned comparison for the first formant was calculated. The F1 difference between <a> and <e> as well as the difference between <e> and <i> was significant (F1 <a>-<e>: t=3.10, p<0.003; F1 <e>-<i>: t=2.55, p<0.02), although the difference between <a>
and <i> was not (F1 <a>-<i>: t=0.55, p=0.58).
Table 54: Formant values of the primes in experiment 1 and 2.
VOWEL FORMANT FREQUENCY [Hz]
<a> F1 530
F2 1843
F3 2507
<e> F1 349
F2 2077
F3 2645
<i> F1 498
F2 1571
F3 2381
The vowels <a> and <i> were still distinguishable, though, on the basis of their F2 values which differed significantly in a post-hoc analysis (F2 <a>-<i>: t=4.66, p<0.001). Furthermore, <i> differs from the other two vowels in its F3 value (t=3.86, p<0.001). Together with its lower F2 values, this indicates that its realisation is in fact rounded.
Euclidian distances between all three vowels also differed significantly. Euclidian distances were calculated in the [F2-F1]/[F1] vowel space and a single-factor ANOVA was applied subsequently. The factor was DISTANCE TYPE (<a>-<i> <a>-<e> <e>-<i>). All three distances differed significantly from each other (F[2,45]=18.13, p<0.001, cf. Table 55).
Table 55: Euclidian distances of the vowels in the test stimuli.
DISTANCE TYPE DISTANCE [Hz]
<a>-<e> 456
<a>-<i> 293
<e>-<i> 673
The acoustic analysis showed two important points. First, all three vowels of the test items could be distinguished by their formant values. Furthermore, all their Euclidian distances differed. Second, the F1 frequency of <e> is always lower than that of <i>, supporting the findings elsewhere that in NZE, <e>
is realised as a front, high vowel, while <i> is a more centralised mid and rounded vowel. From an acoustic point of view, it is thereby guaranteed that the primes included both high front and mid central vowels (cf. Figure 38).
75 cf. Ladefoged, 2001 and references therein; see also Pfitzinger, 2003, and Kingston, 1991.
- 195 -
Realisations of the Stimuli Vowel (Experiment 1 and 2)
300
Figure 38: Realisations of the test stimuli stem vowels in the F2-F1/F1 space for the indirect semantic priming experiments 1 and 2. The formant values represent the average
across experimental items (primes) and are based on a LPC analysis at the vowelsÊ midpoints.
5.4.2.2 Estimation of vowel categorisation (NZE listeners)
In order to obtain an estimation of how NZE speaker would categorise the vowels <a>, <e> and <i>
along the F1 dimension, a short categorisation study was performed, using semi-synthesised short front
along the F1 dimension, a short categorisation study was performed, using semi-synthesised short front