Effects of consonant manner and vowel height on intraoral pressure and articulatory contact at voicing offset and onset for voiceless obstruents

Abstract

In obstruent consonants, a major constriction in the upper vocal tract yields an increase in intraoral pressure (P(io)). Phonation requires that subglottal pressure (P(sub)) exceed P(io) by a threshold value, so as the transglottal pressure reaches the threshold, phonation will cease. This work investigates how P(io) levels at phonation offset and onset vary before and after different German voiceless obstruents (stop, fricative, affricates, clusters), and with following high vs low vowels. Articulatory contacts, measured using electropalatography, were recorded simultaneously with P(io) to clarify how supraglottal constrictions affect P(io). Effects of consonant type on phonation thresholds could be explained mainly in terms of the magnitude and timing of vocal-fold abduction. Phonation offset occurred at lower values of P(io) before fricative-initial sequences than stop-initial sequences, and onset occurred at higher levels of P(io) following the unaspirated stops of clusters compared to fricatives, affricates, and aspirated stops. The vowel effects were somewhat surprising: High vowels had an inhibitory effect at voicing offset (phonation ceasing at lower values of P(io)) in short-duration consonant sequences, but a facilitating effect on phonation onset that was consistent across consonantal contexts. The vowel influences appear to reflect a combination of vocal-fold characteristics and vocal-tract impedance.

Phonation and laryngeal specification in American English voiceless obstruents

“…While both partially phonated stops and fricatives have much more phonation in the first interval than in the other two, stops in all word positions still have more phonation than fricatives in all word positions in the first interval, as shown in Figure 6. This is consistent with an analysis of airflow in stops and fricatives by Koenig et al (2011), who note that '[c]losely-approximated vocal folds entering stops should facilitate phonation and allow it to persist to a higher level of [intraoral pressure], whereas earlier abduction for fricatives would inhibit phonation' (3235). It is also consistent with the comparison of voiceless fricatives and stops in Docherty (1992), who found that when voiceless stops have phonation during the closure, it tends to be longer in duration than the counterpart phonation in fricatives.…”

“…'edge vibrations' in Lisker & Abramson 1964) -partial phonation that carries over from the preceding sound or that begins during the transition from a consonant to a vowel -is present during the constriction of stops and fricatives. In a study of intraoral air pressure in German, Koenig, Fuchs & Lucero (2011) find that there is an asymmetry in the amount of intraoral pressure (P io ) observed at obstruent edges: P io is greater at phonation offset (at the beginning of the target consonant) than at phonation onset (after the target consonant), which contributes to differences in the proportion of phonation present at the edges of the closure.…”

“…In contrast, just over 10% of phrase-initial fricatives and stops have some partial phonation. The somewhat greater proportion of phonation in phrase-final position as compared to phrase initial position is expected, because of the asymmetry of the lower amount of threshold pressure needed to maintain phonation from a preceding sonorant as compared to the higher level required to initiate it after a pause (Plant, Freed & Plant 2004, Koenig et al 2011.…”

“…However, whereas fricatives are more evenly split between trough and bleed, > 80% of stops with partial voicing are produced with the bleed pattern. An examination of the data suggests that the trough pattern in stops tends to coincide with intervocalic consonants that are produced with a closure, but do not necessarily have a burst, suggesting that the intraoral pressure was relatively low and therefore more conducive to starting the vocal fold vibration necessary for the following vowel/approximant (Koenig et al 2011). As for fricatives, weaker frication at the edges at the moments of transition and overlap between the fricative and adjacent sonorants is more likely to allow for the presence of short periods of edge phonation (Docherty 1992), whereas the typical high pressure and open larynx up to the burst in a voiceless stop ensures that phonation will not begin until after the burst is released (Löfqvist et al 1995, Fuchs & Koenig 2009.…”

Modelling incomplete neutralisation with weighted phonetic constraints

“…In incomplete neutralisation, the reduction of contrast is not due purely to the physical mechanics of articulation. As pointed out by an anonymous reviewer, the VOT contrast is decreased before low vowels as compared to high vowels; the link between VOT and vowel height is likely mechanical (Chang et al 1999, Koenig et al 2011), rather than an effect of a speaker's grammar per se . Such cases are not normally considered to be incomplete neutralisation.…”