Vowel Reduction in Russian The Categorical and the Gradient

Vowel Reduction in Russian: The Categorical and the Gradient I. Introduction • Phonological vowel reduction (hereafter VR): neutralization of vowel quality contrasts in unstressed syllables. • Figures in recent theoretical literature (e.g. Barnes 2002, Beckman 1998, Crosswhite 2001, Flemming 2oo1a and b, Steriade 1994) as an example of a pattern of Positional Neutralization with relatively clear phonetic underpinnings. • Understanding the relationship between these phonetic underpinnings and the phonological grammar in patterns such as VR is a central task of current work on the phonetics-phonology interface. 2. Russian Vowel Reduction 2.1. Facts • Contemporary Standard Russian: traditionally claimed to display two distinct patterns or degrees of VR, one for the syllable immediately preceding the tonic (here, first pretonic), and one for all other unstressed syllables. • Five vowels contrast in stressed syllables1. • Mid vowels do not surface in unstressed syllables. (1) Stressed vowel inventory i e o u 1 pretonic s fi i a fi u 2 pretonic, posttonic s i ´ u a • Focus of this talk: /a/ vs. /o/ • /a/ and /o/ contrast in stressed syllables, but this contrast is neutralized in unstressed syllables as follows: (2) a. /a/, /o/ fi [a]/[å] in first pretonic syllables, a.k.a. Degree 1 reduction b. /a/, /o/ fi [´] in other unstressed syllables, a.k.a. Degree 2 reduction 1 See Padgett 2001 and sources therein for arguments against a contrast between /i/ and the high central vowel /ˆ/. -1- (3) VR in Contemporary Standard Russian /o/ mo@l´d´stJ bo@lJ youth pain DEGREE 1 REDUCTION DEGREE 2 REDUCTION malo@dJInJkJIj young (dim.) m´lado@j young balJe@tJ to hurt b´lJIvo@j pain (adj.) /a/ sta@rˆj ra@zum old (adj.) reason starJi@k razu@mn´ STRESSED • old man st´rJIna@ wisely (adv.) r´zumJe@tJ old times to understand Several exceptions to the pattern described above are recognized: (4) No reduction to schwa in absolute word-initial position /odno»mu/ /obi»Zajet/ [adna»mu] [abJi»Zajit] 'one' (dat.sg.) *[´dna»mu] 'insult, abuse' (3sg.) *[´bJi»Zajit] (5) No reduction to schwa in hiatus before [a] /odnoo»braznˆj/ -> [adnaa»braznˆj] /sootno»Senije/ -> [saatna»SenJije] 'monotonous' ‘relationship’ *[adn´a»braznˆj] *[s´atna»Senije] (6) No reduction to schwa in absolute phrase-final syllables (Matusevic& 1976: 102, Zlatoustova 1962: 109-139) 2.2. Previous approaches • Two recent OT accounts: a. Alderete (1995): Faithfulness constraints parameterized to the head foot (i.e. the stressed syllable and first pretonic) rank higher than markedness constraints against [a] in unstressed syllables, which in turn outrank general Faithfulness constraints. b. Crosswhite (2001): vowels outside the head foot cannot bear moras, but [a] cannot be non-moraic, and so is realized as schwa. • Both these approaches must present essentially diacritic solutions to the exceptional patterns described above. • All previous accounts of VR in Russian treat both Degree 1 and Degree 2 reduction patterns as phonological, i.e. as changing phonological category membership through manipulation of distinctive feature specifications. 2.3. Phonetic underpinnings of phonological vowel reduction • Phonological patterns such as elimination of mid vowels and raising of low vowels in unstressed syllables have been claimed to have their source in the reduction of phonetic vowel durations in unstressed syllables. -2- • Languages with phonological vowel reduction are almost invariably those languages with a stress accent strongly and reliably cued by a difference in vowel duration between stressed and unstressed syllables (Lehiste 1970). • Shortening of vowels in unstressed syllables leads to undershoot of more open target articulations of non-high vowels. Raising of these creates a compressed vowel space in which contrasts are likely to be misperceived and to collapse over time (See Barnes 2002, Flemming 2001a for discussion). • This accounts for the typological generalization that in VR systems, vowel height contrasts are the first to go. When this happens, the vowels to go are almost invariably the mid and low vowels. High vowels stay put. 3. One experiment, begetting another... • Though phonological VR has clear phonetic roots diachronically in the shorter durations associated with unstressed syllables in VR languages, to what extent phonetic duration is active in triggering vowel reduction synchronically is still poorly understood. • The following experiment was designed to investigate this question. 3.1. Methodology • Experiment #1 was designed to determine what, if any, active role phonetic duration plays in the realization of vowel reduction in reduction. • Test words: 72 Russian trisyllables 12 stressed /a/ 12 1 pretonic /a/ 12 2 pretonic /a/ 12 stressed /o/ 12 1 pretonic /o/ 12 2 pretonic /o/ • All target vowels were located in open syllables followed by unpalatalized voiced or voiceless stops and preceded by unpalatalized voiced stops, voiceless stops, or laterals. • Tokens were embedded in frame sentences of the form Mashka X skazala, 'Mashka said X'. Each token appeared twice for a total of 144 sentences. • Sentences were randomized and arranged in blocks of 12. • Subjects, one male from St. Petersburg, one female from Ufa, student-age native speakers of Russian, were instructed to read through each block of sentences once slowly and then once again as quickly as possible to achieve maximum variation in vowel durations. • Sessions were recorded directly to CD at a sampling rate of 44.1 KHz. Duration and LPC formant measurements were taken using Praat 4.1.11 speech analysis software (Copyright@1992-2003 by Paul Boersma and David Weenink). -3- 3.2. Results 3.2.1. Mean values for duration and F1 (7) Speaker 1 2 Duration F1 1 PRETONIC 84 ms. 553 Hz 2 PRETONIC 41 ms 462 Hz 1 PRETONIC /a, o/ 68 ms. 726 Hz 2 PRETONIC /a, o/ 25 ms. 492 Hz (8) Speaker 2 STRESSED /a/ 86 ms. 722 Hz Duration F1 /o/ 73 ms 466 • Neither speaker had any significant difference between unstressed /a/ and /o/ in any position. This contrast is completely neutralized. • Speaker 1 shows a mean F1 for 1 pretonic /a, o/ dramatically lower than a typical value for stressed /a/. Reflects traditional transcription of the former as [!] (e.g. Matusevic¬ 1972, Avanesov 1968). Probably more like [å], see Barnes 2002, chapter 2, for details. • For Speaker 2, no significant difference was found between F1 values for 1 pretonic /a, o/ and stressed /a/. 3.2.3. Vowel height as a function of phonetic duration The following displays the results of linear regression analyses of the relationship between vowel duration and vowel height for Speakers 1 and 2 in Experiment 1. • (9) Speaker 1 a. R (92) = .179, p > .05 b. R (60) = .602, p <.0001 First Pretonic /a/ and /o/ Second Pretonic /a/ and /o/ 800 600 700 500 400 500 Series1 400 Linear (Series1) 300 R2 = 0.0145 F1 in Hz F1 in Hz 600 Series1 300 Linear (Series1) 200 2 R = 0.3981 200 100 100 0 0 0 20 40 60 80 100 120 0 Duration in ms. 20 40 60 80 Duration in ms. 2 Speaker 1 in fact read a somewhat earlier version of the same experiment containing fewer words and not testing vowels in stressed syllables. -4- Speaker 1: unstressed /a/ and /o/ 800 700 600 F1 in Hz 500 Series1 400 Series2 300 200 100 0 0 20 40 60 80 100 120 Duration in ms. (10) Speaker 2 a. R (146) = .142, p > .05 b. R (78) = .644, p <.0001 Second Pretonic /a/ and /o/ First Pretonic /a/ and /o/ 700 1000 900 600 800 500 Series1 500 Linear (Series1) 400 F1 in Hz 600 2 R = 0.0297 300 400 Series1 300 Linear (Series1) 2 R = 0.4204 200 200 100 100 0 0 0 20 40 60 80 0 100 10 20 30 40 Duration in ms. Duration in ms. Speaker 2: unstressed /a/ and /o/ 1000 900 800 700 F1 in Hz F1 in Hz 700 600 Series1 500 Series2 400 300 200 100 0 0 10 20 30 40 50 60 Duration in ms. -5- 70 80 90 100 50 3.3 Interim summary • Neutralization of /a/ and /o/ in unstressed syllables is categorical. No significant difference between these underlying categories is preserved. This is true regardless of position relative to stress. • Reduction to schwa in Degree 2 reduction environments has a clear gradient character. Vowel height is strongly dependent on vowel duration. A cline of F1 values is recorded between more [a]-like values on longer vowels and more schwa-like values on shorter vowels. • Categorical vs. gradient application is argued to be a defining distinction between symbolic phonological processes and quantitative phonetic processes (see e.g. Keating 1988c, Cohn 1990, Zsiga 1993, Myers 2000, Barnes 2002, inter alia) • Hypothesis: given the duration-dependent cline of F1 values produced in Degree 2 reduction contexts, there is no reason to think the phonology has any role in (or access to) reduction of unstressed /a, o/ to schwa. The merger of /a/ and /o/ in unstressed syllables, on the other hand, is clearly categorical and phonological. 4. Experiment #2: Hyperarticulation • F1 values for Degree 2 reduction in Experiment 1 approach, but fail to clearly attain canonical [a]-like qualities. Experiment 2 seeks to draw out this result more clearly. 4.1. Methodology • Test words were 20 trisyllables of Russian, 10 with /a/, and 10 with /o/ in open second pretonic syllables. All target vowels were located in open syllables followed by unpalatalized voiced or voiceless stops and preceded by unpalatalized voiced stops, voiceless stops, or laterals. • Target words were framed in sentences of the form Po-moemu on X skazal, 'Seems to me he said X'. • Speakers were four student-age native speakers of Russian: three females raised in Ufa, Saint Petersburg, and Moscow respectively, and one male, from Moscow. • Sentences were embedded in a longer list of similar sentences and randomized. • Following an experimental paradigm used in, e.g. Johnson, Flemming and Wright 1993, subjects read each sentence, and then were asked twice to repeat themselves by an experimenter simulating incomprehension (speakers were informed this would occur before the experiment began): (11) Sample dialogue Sp: Po-moemu on X skazal. JB: Ah? Ne ponjal. Sp: X on skazal! JB: Sµto eto on skazal??!! Sp: X! 'Seems to me he said X' 'Huh? I didn't get that.' 'He said X!' 'He said what??!!' -6- • Each word received three repetitions, the second and third with substantial hyperarticulation. • All speakers reported finding this experimental methodology deeply exasperating. • Sessions were recorded directly to CD at a sampling rate of 44.1 KHz. Duration and LPC formant measurements were taken using Praat 4.1.11 speech analysis software (Copyright@1992-2003 by Paul Boersma and David Weenink). 4.2. Results (12) Vowel height as a function of phonetic duration Speaker 1 Speaker 2 R (54) = .618, p < .0001 R (58) = .934, p < .0001 Speaker 1: second pretonic /a/ and /o/ Speaker 2: second pretonic /a/ and /o/ 700 1200 600 1000 Series1 300 Linear (Series1) 2 R = 0.371 200 F1 in Hz 400 800 Series1 600 Linear (Series1) 400 R2 = 0.8741 200 100 0 0 0 10 20 30 40 50 60 0 50 100 Duration in ms. 150 200 250 Duration in ms. c. Speaker 3 d. Speaker 4 R (58) = .718, p < .0001 R (57) = .84, p < .0001 Speaker 4: second pretonic /a/ and /o/ Speaker 3: second pretonic /a/ and /o/ 1000 1000 900 900 800 800 700 700 600 Series1 500 Linear (Series1) 400 2 R = 0.5154 300 F1 in Hz F1 in Hz F1 in Hz 500 600 Series1 500 Linear (Series1) 400 2 R = 0.7052 300 200 200 100 100 0 0 0 10 20 30 40 50 60 70 0 80 20 40 60 80 Duration in ms. Duration in ms. -7- 100 120 140 160 (13) All speakers, raw scores: r (228) = .737, p < .0001 Second Pretonic /a/ and /o/: Raw Scores 1200 1000 F1 in Hz 800 600 Series1 Linear (Series1) 400 R2 = 0.5405 200 0 0 50 100 150 200 250 Duration in ms. • To escape problems of interspeaker comparison of vowel formant values, raw duration and F1 values for all speakers were converted to a standardized z-score format3, yielding the following results: (14) All speakers, z-scores: R (228) = .803, p < .0001 Second Pretonic /a/ and /o/: standardized 5 4 3 F1 2 Series1 Linear (Series1) 1 R2 = 0.6456 0 -3 -2 -1 -1 0 1 2 3 4 5 6 -2 Duration 4.3. Discussion • All speakers show a highly significant correlation between vowel duration and vowel height. Reduction of /a, o/ to [´] applies gradiently, with syllables afforded sufficient duration by hyperarticulation showing little or no vowel raising. 3 zx = ( x - mx ) / sx, , where m is the mean for a given set of values, and s the standard deviation. -8- • Crucially, no amount of lengthening is sufficient to restore an underlying /o/ in an unstressed syllable. The neutralization of /a/ and /o/ in unstressed syllables is categorical and phonological, displaying no sensitivity whatsoever to phonetic duration. • Were the non-application of reduction to schwa in clear speech in any sense a paralinguistic effect, e.g. a spelling pronunciation, we would expect restoration of /o/ in unstressed syllables as well. This never occurs. 5. Conclusions • There are indeed two types of vowel reduction in Russian. • Only one is accomplished in the phonology. The other is a gradient process accomplished by the phonetics. /´/ is not a phonological category in Russian. • This conclusion simplifies Russian phonology greatly, while requiring nothing of the phonetics other than the capacity to implement fine-grained durational patterns conditioned by prosodic structure, a capacity it must have under any circumstances. • Additional payoff: the seemingly-arbitrary exceptions to Degree 2 reduction detailed in 2 above now make perfect sense. Absolute word-initial position, hiatus before another [a], and absolute phrase-final position are all environments in which additional phonetic duration is likely to be present. Duration-dependent phonetic reduction to schwa does not then apply. • Any model of the phonetics-phonology interface must be equipped to handle not only the distinction between categorical and gradient processes, but also the complete lack of sensititivy of categorical processes to their phonetic environments. -9-