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P Hoole

Publications and source records attributed to P Hoole.

7 recordsLinked to original sources

[MRT sequences as a database for a visual articulatory model].

Articulatory models can be used in phoniatrics for the visualisation of speech disorders, and can thus be used in teaching, the counselling of patients and their relatives, and in speech therapy. The articulatory model developed here was based on static MRI data of sustained sounds. MRI sequences are now being used to further refine the model with respect to speech movements. Medio-sagittal MRI sections were recorded for 12 consonants in the symmetrical context of the three point vowels [i:], [a:] and [u:] for this corpus. The recording-rate was eight images/s. The data show a strong influence of the vocalic context on the articulatory target-positions of all consonants. A method for the reduction of the MRI data for subsequent qualitative and quantitative analyses is presented.

Articulation Disorders↗

On the lingual organization of the German vowel system.

A hybrid PARAFAC and principal-component model of tongue configuration in vowel production is presented, using a corpus of German vowels in multiple consonant contexts (fleshpoint data for seven speakers at two speech rates from electromagnetic articulography). The PARAFAC approach is attractive for explicitly separating speaker-independent and speaker-dependent effects within a parsimonious linear model. However, it proved impossible to derive a PARAFAC solution of the complete dataset (estimated to require three factors) due to complexities introduced by the consonant contexts. Accordingly, the final model was derived in two stages. First, a two-factor PARAFAC model was extracted. This succeeded; the result was treated as the basic vowel model. Second, the PARAFAC model error was subjected to a separate principal-component analysis for each subject. This revealed a further articulatory component mainly involving tongue-blade activity associated with the flanking consonants. However, the subject-specific details of the mapping from raw fleshpoint coordinates to this component were too complex to be consistent with the PARAFAC framework. The final model explained over 90% of the variance and gave a succinct and physiologically plausible articulatory representation of the German vowel space.

Female↗

Do airstream mechanisms influence tongue movement paths?

Velar consonants often show an elliptical pattern of tongue movement in symmetrical vowel contexts, but the forces responsible for this remain unclear. We here consider the role of overpressure (increased intraoral air pressure) behind the constriction by examining how movement patterns are modified when speakers change from an egressive to ingressive airstream. Tongue movement and respiratory data were obtained from 3 speakers. The two airstream conditions were additionally combined with two levels of speech volume. The results showed consistent reductions in forward tongue movement during consonant closure in the ingressive conditions. Thus, overpressure behind the constriction may partly determine preferred movement patterns, but it cannot be the only influence since forward movement during closure is usually reduced but not eliminated in ingressive speech.

Air↗

Syllabic timing in dysarthria.

A new, intensity-based method of measuring syllable duration was used to assess syllabic timing in 75 patients with dysarthria of predominantly traumatic and cerebro-vascular origin and in 30 normal subjects. The applied speech tasks included repetitions of sentences containing chains of plosive-vowel-syllables. The logarithm of the duration of the syllable carrying sentence accent proved to be particularly highly correlated with perceived speech rate. Among the potential sources of temporal variability, segmental influences and the influence of sentence stress were examined. Further, the between-sentence variation of syllable duration was assessed. The resulting measures of variability were correlated with the severity of dysarthric impairment. A strengthening of normal effects was found in the consonant-related variation, whereas intrinsic vowel effects and the influence of sentence stress were largely reduced. These results are discussed from the viewpoint of timing theories in speech and limb motor control. They are considered to provide a valuable background against which the speech impairments of specific neurologic groups can be tested.

Adolescent↗

Does the closed syllable determine the perception of 'momentary tempo'?

Recent investigations on the perception of the temporal course of speech have dealt with stress-beat phenomena and isochrony and also with 'momentary tempo'. In our attempts to reproduce and modify some of the experiments undertaken by Ventsov on 'momentary tempo' we came to the conclusion that statements on 'momentary tempo' cannot be formulated in terms of closed syllable duration or vowel onset to vowel onset interval either, but rather in terms of an articulatory theory similar to the one proposed by Menzerath and de Lacerda using the notion of 'point of Koartikulation'.

Humans↗

A comparative investigation of coarticulation in fricatives: electropalatographic, electromagnetic, and acoustic data.

The principal aim of this investigation was to compare coarticulatory effects at different levels of the speech production system, in order to gain insight into the relations between the different levels. To this end, the relative magnitudes of carryover and anticipatory coarticulation with adjacent vowels were measured at the midpoints of the two lingual fricatives /s/ and /integral of/ in two speakers each of English, French, and German. Linguopalatal contact patterns derived from electropalatographic recordings were compared with an analysis of the acoustic output. The results indicated, firstly, that mismatches between articulatory and acoustic results are not uncommon. Secondly, and more surprisingly, while there was no difference in the overall magnitude of coarticulatory effects for /s/ and /integral of/, not all speakers showed a predominance of the same coarticulatory direction on both fricatives; this complicated the observed tendency for the predominance of carryover coarticulation to be greater in German and English than in French. Two speakers were retested using comparative analyses of electropalatography and electromagnetic articulography. These two procedures gave a closely parallel picture of lingual coarticulatory regularities (while complementing each other in terms of characterizing articulation). The implications of these results for identifying language-specific coarticulatory regularities are discussed.

Female↗