An acoustic phonetic analysis of Lewis Gaelic stop consonants
Claire Nance and Jane Stuart-SmithUniversity of Glasgow
[email protected]@englang.arts.gla.ac.uk
Overview
• Stops in Gaelic• Approaches• Research questions• Methods• Results• Conclusions
Stops in Gaelic
• Word initial /ph th kh/ and /p t k/
• Word medial and word final /hp ht hk/ and /p t k/ (Ladefoged et al. 1998)
• (Also palatalised vs. velarised distinction)
Initial stops
bog ‘soft’
pòg ‘a kiss’
VOTVOT Vowel voicingVowel voicing ClosureClosure
Vowel voicingVowel voicing ClosureClosure
VOT vs. Pre-aspiration
• ‘the interval between the release of the stop and the onset of glottal vibration, that is, voicing’ (Lisker and Abramson 1964:389)
• ‘delay in the offset of normal voicing’ (Laver 1994:150)
• Aspiration ≠ pre-aspiration (Silverman 2003)
Medial and final stops
smoc ‘smoke’
snog ‘nice’
Vowel voicingVowel voicing CloseClose
Pre-aspPre-asp
Vowel voicingVowel voicing ClosureClosure
Pre-aspiration zoom in
smoc ‘smoke’
Vowel voicingVowel voicing CloseClose
Pre-aspPre-asp
Pre-aspiration zoom in
smoc ‘smoke’
CloseCloseCloseClose
Pre-aspPre-aspBreathy VoiceBreathy Voice
Approaches
• Ladefoged et al. (1998)• Ní Chasaide (1985)• Sociophonetics and consonants (Foulkes and
Docherty 1999)
Research questions
• A more complete analysis than Ladefoged et al. (1998)
• Is this system undergoing apparent time change?
Methods
• Native speakers of Lewis Gaelic• 3 ‘older’ (45-55), 3 ‘younger’ (20-24)• Recording conditions• Word list data• 2257 tokens analysed• Non-parametric statistical tests
Measures: durational
• Initial: VOT, vowel• Medial: vowel, modal voice, pre-aspiration,
breathy voice, voiceless pre-aspiration, closure, VOT
• Final: vowel, modal voice, pre-aspiration, breathy voice, voiceless pre-aspiration, closure
a c a
Measures: durational
• Segmenting on the waveform in Praat
Modal voiceModal voiceVowelVowel
Pre-aspirationPre-aspirationBVBV NoiseNoise
Measures: dynamic noise-based
• Quantification of noisiness• Anticipatory and carry-over effects (Gobl and Ní
Chasaide 1999)• Adapted zero crossing rate (Gordeeva and Scobbie
2010)• Collaborating with Olga [email protected]• Measure of noise from the glottis in periodic and
aperiodic sections• BV measures (HNR, spectral tilt, jitter shimmer)• Standard zero crossings (Bombien 2006)
• BP filtered at 5000Hz and 1.5 x F0• Effects of filtering (Gordeeva and Scobbie 2010:18)
• Perceptual superiority of this measure
BP ZCR
‘bus’ unfiltered
‘bus’ filtered
Applied to initial stops
càl ‘cabbage’
Results: durational
• VOT in initial stops• Effect of place of articulation (cf. Cho and
Ladefoged 1999)
n = 1285
Results: durational
• Vowel length – the action is in the aspirated series (cf. Kessinger and Blumstein 1997)
n = 642
Results: BP ZCR – Initial system
n = 270
Medial system
• Pre-aspiration longer in aspirated series• Some breathy voice in unaspirated• VOT ns.
n = 54
Medial system
• Vowel length (cf. Ní Chasaide 1985)
% duration of pre-aspiration word medial /ht/ according to vowel length
n = 36
Results: BP ZCR – Medial system
n = 180
Apparent time change
• VOT longer in aspirated series for younger speakers (aspirated series again)
n = 642
Results: BP ZCR – Initial change
n = 90
Speech rate
• Young people speak faster?• Effects on VOT (Allen et al. 2003, Pind 1995)• Ratios
VOTVOT VowelVowel
Pre-aspirationPre-aspirationVowelVowel
BurstBurst
Vowel Start
Vowel Start
Vowel end
Vowel end
ClosureClosure
Apparent time change
• Pre-aspiration shorter• Pre-aspiration different
% modal voice, breathy voice and voiceless pre-asp in word medial stops
n = 157
Results: BP ZCR – Medial change
n = 36
Summary of results
• YP longer VOT• YP shorter and different pre-aspiration• Benefits of a noise-based dynamic measure • Results suggest can separate phonemic
categories and age groups across the syllable
Conclusions: systems
• Support for Kessinger and Blumstein (1997): aspirated series show most variation
• Phonetically aspiration and pre-aspiration are not the same
• BUT aspiration functions as a system:– Vowel length– Change in younger speakers
Conclusions: apparent time change
• Pre-aspiration results:– Diachronic instability of pre-aspiration (Silverman
2003)– Influence of English? (Contact, obsolescence…)– Greying of phonemic categories due to lexical attrition
• VOT results:– Stops functioning as a system so somehow
compensating?
• Implications
References• Allen, J., Miller, L., and DeSteno, D., 2003. Individual talker differences in voice-onset-time. Journal of Acoustic
Society of America, 113:1, pp. 544-552• Bombien, L., 2006. Voicing alterations in Icelandic – a photoglottographic and acoustic investigation. In J.
Harrington, C. Mooshammer, F Kleber, eds., Arbeitsberichte de sInstituts fürPhonetik der Universität Kiel, 37, pp. 63-82. Kiel: Universität Kiel
• Cho, T., and Ladefoged, P., 1999. Variation and universals in VOT: evidence from 18 endangered languages. Journal of phonetics, 27, pp. 207-229
• Foulkes, P., and Docherty, G., 1999. Urban Voices. London: Arnold• Gobl, C., and Ní Chasaide, A., 1999. Voice source variation in the vowel as a function of consonantal
context. In W. J. Hardcastle and N. Hewlett, eds., Coarticulation. Cambridge: CUP. pp. 122-134• Gordeeva, O., and Scobbie, J., 2010. Preaspiration as a correlate of word-final voice in Scottish English fricatives. In
S. Fuchs, M. Toda, M. Zygis, eds., Turbulent sounds: an interdisciplinary guide. Berlin: Mouton de Gruyter• Ladefoged, P., Ladefoged, J., Turk, A., St. John, S., 1998. Phonetic structures of Scottish Gaelic. Journal of the
international phonetic association, 28, pp. 1-41• Kessinger, R., and Blumstein, S., 1997. Effects of speaking rate on voice-onset-time in Thai, French, and English.
Journal of Phonetics, 25:2, pp. 143-168• Laver, J., 1994. Principles of phonetics. Cambridge: Cambridge University Press• Lisker, L., 1957. Closure duration and the intervocalic voiced-voiceless distinction in English. Language, 33:1, pp.
42-49• Lisker, L., and Abramson, A., 1964. A cross-language study of voicing in initial stops: Acoustical measurements.
Word 20, pp. 384-422• Ní Chasaide, A., 1985. Preaspiration in phonological stop contrasts: an instrumental phonetic study. PhD thesis,
University of Bangor• Pind , J . 1995. Speaking rate , voice-onset time , and quantity: The search for higher-order invariants for two
Icelandic speech cues. Perception and Psychophysics, 57, pp. 291–304• Silverman, D., 2003. On the rarity of pre-aspirated stops. Journal of linguistics 39:3, pp. 575-598
Mòran taing
Claire Nance and Jane Stuart-Smith
University of Glasgow
A word on breathy voice
• Ní Chasaide (1985:139) sees BV as purely physiological
• Some evidence to support this: no place effect• Some against: YP have more in velars
Word initial apparent time change
• Comparison to Ladefoged et al. (1998)• Word initial /th/ and /t/
Word medial apparent time change
• Word medial /hk/, noise and VOT
Closure durations
• Closure durations (Lisker 1957)• Longer in aspirated series• We found significantly longer closure
durations for coronals and bilabials in the aspirated series