e.g., sent, dense, bent, lent

1. Discussion of Experiments 1 & 2 Implications for Theories of Sound Change • Two experiments studied the temporal relation between extent of coarticulation and the segmental source of that coarticulation. Exp. 1 showed for CVN and NVC sequences that, the shorter the N duration, the more extensive the vowel nasalization. Exp. 2 showed this same pattern for CVNCs differing in coda voicing. • The V/N trade-off corresponds with constant-sized nasal gesture for CVNs and NVCs. In contrast, for CVNCs, the extreme pre-voiceless N shortening that sometimes occurred was not fully offset by heavy vowel nasalization. We attribute shorter total nasalization in voiceless contexts in part to the shortness of pre-voiceless vowels: for these short vowels, even total V nasalization did not fully offset N shortening for some speakers. (Note in the scatter plots that, despite the heavy V nasalization for Speakers 4 and 5, these speakers' productions showed the poorest the goodness of fit between V and N duration.) ~ ~ Duration of Total Nasalization (V + N) for CVN and NVC ~ Duration of Total Nasalization (V + N) for CVNC ~ ~ ~ V N 182 ms ~ e.g., sent, dense, bent, lent • The spatial and temporal extent of coarticulatory vowel nasalization has been shown to vary substantially across speakers, contexts, speaking rates, and languages (e.g., Kent et al., 1974; Clumeck, 1976; Krakow, 1993). • The hypothesis underlying this study is that temporal variation in coarticulatory vowel nasalization is in part offset by variation in the duration of the flanking nasal consonant (N), so that total nasalization (V + N) across the syllable is relatively stable. That is, we predict that, the shorter the "trigger" N, the greater its coarticulatory effects on an adjacent V. • We further hypothesize that listeners are sensitive to total nasalization across the syllable, but are relatively insensitive to the source of the nasalization, treating nasality on the vowel and the nasal murmur as perceptually equivalent. ~ N V ~ V N • Other languages also provide evidence of an inverse relation between N duration and its coarticulatory effects: • English (our measures): VN (shorter N, more V NAS) vs. NV • VNT/S (shorter N, more V NAS) vs. VND/Z • Thai (Onsuwan, in prep): V:N (shorter N, more V NAS) vs. VN: • Italian (Busà, 2003): VNS (shorter N, more V NAS) vs. VNT • The phonological literature (e.g., Hajek, 1997) shows that it is precisely those contexts that have shorter N and heavier coarticulatory nasalization (i.e., long Vs; coda Ns especially when followed by fricatives or voiceless obstruents) that are most likely to trigger the sound change VN > V. e.g., send, dens, bend, lend 181 ms ~ ~ N V Duration (ms) ~ • The inverse relation between V and N within the syllable yields the same totalduration of the lowered velic gesture (V + N) for CVN and NVC sequences. ~ ~ • Unlike Exp. 1, where total nasalization (V + N) was constant across CVN / NVC sequences, total nasalization in Exp. 2 was not constant for CVNC sequences differing in coda voicing. • However, as borne out in the scatter plots for individual speakers below, the data show a clear trend in the direction of an inverse relation between V nasalization and N duration. ~ Onset Vowel Nasalization Vowel Offset/ Nasal Onset • The data for CVN and NVC sequences in Experiment 1 are consistent with the hypothesis that the shorter the "trigger" N, the greater its coarticulatory effects on a flanking V. For these sequences, the V/N relation would appear to be the result of a constant-sized velum gesture across the different syllable types. • What, then, serves as the trigger for the loss of the N in such changes? We propose that the perceptual consequence of the V/N co-variation in production is that listeners treat the two "sites" of nasalization as perceptually equivalent. Our perceptual data (not presented here) support this by showing that listeners are sensitive to total nasalization across the syllable but are relatively insensitive to the source (V or N) of the nasalization. ~ ~ ~ Vowel Onset Nasal Offset 5pSC17. Nasals and Nasalization: The Interplay between Segmental Duration and Coarticulation Samantha Sefton and Patrice Speeter Beddor Department of Linguistics, University of Michigan Results Methods Experiment 2: Anticipatory Nasalizationin Voiced and Voiceless Contexts Abstract Summary of Exp. 2 Duration of Vowel Nasalization (in ms) for CVN and NVC Speakers: 5 native speakers of Midwestern English Two experiments were conducted on English to test the hypothesis that the temporal extent of coarticulatory vowel nasalization is inversely related to the duration of the source of coarticulation. Experiment 1 investigated patterns of carryover (NVC) and anticipatory (CVN) vowel nasalization, and the overall timing of nasalization across the syllable. Acoustic analysis of CVN and NVC words (e.g., seen/niece, pin/nip, ten/net) produced by five speakers showed that, although vowel nasalization is temporally more extensive in CVN than in NVC sequences, N is shorter in CVN than in NVC, so that there was no significant overall difference in total nasalization between the two syllable types. Experiment 2 tested similar timing patterns in CVNC syllables, where N duration varied as a function of the voicing of the coda C (e.g., sent/send, bent/bend). Acoustic measures of productions of five English speakers again showed that the shorter the N, the greater the vowel nasalization. Findings for selected other languages (Thai, Italian) provide further evidence of the inverse relation. These patterns have implications for theories of phonological change. • In /nC/ sequences, /n/ is substantially shorter when C is voiceless (/s t/) than when C is voiced (/z d/).The productions of all speakers show that, the shorter the duration of /n/, the longer the nasalization on //. Purpose Word list: Randomized list (6 repetitions) of CVN and NVC words, where V = /i I e ә/, recorded in a sentence context: Say ___ quickly. Results are reported for 28 CVN and NVC pairs, where a pair consists of mirror-image words (e.g., team/meet, pin/nip, tame/mate), for the vowels /i I e /. Acoustic analyses: based on a combination of waveform, spectrographic, and FFT displays Temporal measures: Spectral measure: V duration Onset of V nasalization N duration Duration of V nasalization Nasal murmurs are shorter before voiceless than before voiced obstruents. This shortening is substantially greater than the difference in N durations for CVN vs. NVC studied in Exp. 1. Exp. 2 tests whether pre-voiceless shortening of N is accompanied by increased anticipatory vowel nasalization, so that total nasalization across the syllable remains relatively constant. Methods Speakers: 5 native speakers of American English. (Note: in order to test for variation in coarticulatory nasalization, only tokens from speakers who did not heavily nasalize vowels in all VNC contexts were measured.) Word list: Randomized list (5-7 repetitions) of /CC/ and /CnC/ words, where coda C = /s t d z/ (e.g., bent, bend, sent, send, sense, dense, dens). Recorded in a sentence context: Say ___ quickly. Acoustic analyses: Same as in Experiment 1 /i/ /I/ /e/ // • For each vowel quality, coarticulatory vowel nasalization was longer in the anticipatory CVN condition than in the carryover NVC condition (average difference: 21 ms). This result is as expected from the current literature. • We note that greater anticipatory than carryover nasalization was not due to differences in vowel duration: overall vowel durations did not differ in CVN and NVC conditions. However, for both CVN and NVC, V nasalization was longer for the longer tense vowels (/i e/) than for the shorter lax (/I/) vowels. Identifying onset/offset of V nasalization: Beginning at vowel onset (or vowel offset, for carryover nasalization), FFT displays were inspected in 10 ms increments. Onset of nasalization was identified as the first display with a clear low-frequency nasal formant (FN) and/or a broadening of F1 bandwidth and lowering of F1 amplitude. The FFT-based decision was verified by inspecting the corresponding spectrographic display (e.g., low-frequency spectral fill) and listening. Measures are illustrated in the following display: Motivation and Hypotheses Results Nasal Consonant Duration (in ms) for CVN and NVC Two Production Experiments • The production hypothesis—that is, that the temporal extent of coarticulatory vowel nasalization is inversely related to the duration of the flanking nasal murmur—is consistent with sporadic evidence from VN sequences in the existing literature (e.g., Malécot, 1960; Cohn, 1990; Busà, 2003). • The production hypothesis is tested here for English for two contextual conditions expected to give rise to differing degrees of coarticulatory nasalization: Experiment 1: Anticipatory (VN) and carryover (NV) nasalization Experiment 2: Anticipatory nasalization in voiceless (Vnt, Vns) and voiced (Vnd, Vnz) contexts /i/ /I/ /e/ // • In each vowel context, Ns were longer in NVC than in CVN sequences (average difference: 18 ms). This outcome is consistent with the prediction of an inverse relation between V nasalization and N duration. Spectrogram and waveform of the word dame (/dem/) produced by Speaker 1. Black arrows indicate location of segmental boundaries. The blue arrow indicates the onset of anticipatory nasalization for /e/. References Busà, M. G. (2003). Vowel nasalization and nasal loss in Italian. Proceedings of the 15th International Congress of Phonetic Sciences, pp. 711-714. Barcelona, Spain. Clumeck, (1976). Patterns of soft palate movements in six languages. J. Phonetics 4, 337-351. Cohn, A.C. (1990) Phonetic and phonological rules of nasalization. UCLA Working Papers in Phonetics 76. Flege, J.E. (1988). Anticipatory and carry-over nasal coarticulation in the speech of children and adults. J. Speech Hear. Res. 31, 525-536. Hajek, J. (1997). Universals of Sound Change in Nasalization. Blackwell. Kent, R.D., Carney, P.J., & Severeid, L.R. (1974). Velar movement and timing: evaluation of a model of binary control. J. Speech Hear. Res. 17, 470-488. Krakow, R.A. (1993). Nonsegmental influences on velum movement patterns. In Nasals, Nasalization, and the Velum (ed. by M.K. Huffman & R.A. Krakow), pp. 87-113. Academic. Malécot, A. (1960). Vowel nasality as a distinctive feature in American English. Language 36, 222-229. Onsuwan, C. (In preparation). Temporal relations between consonants and vowels in Thai syllables. Univ. of Michigan doctoral dissertation. Rochet, A.P. & Rochet, B.L. (1991). The effect of vowel height on patterns of assimilatory nasality in French and English. Proceedings of the 12th International Congress of Phonetic Sciences 3. Aix-en-Provence, France. Experiment 1:Anticipatory and Carryover Nasalization Purpose Experiment 1 tests whether VN and NV sequences in Midwestern English differ in both extent of coarticulatory V nasalization and N duration. Previous studies of English lead us to expect more extensive anticipatory than carryover V nasalization (e.g., Flege, 1988; Rochet & Rochet, 1991). Summary of Exp. 1 Consecutive spectral sections taken in 10 ms increments from the onset to two-thirds through /i/ in deem (/dim/). The arrows in the last five illustrations indicate the low-frequency nasal formant. Work supported by NSF