Philip Hoole

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.

Jaw and order.

It is well-accepted that the jaw plays an active role in influencing vowel height. The general aim of the current study is to further investigate the extent to which the jaw is active in producing consonantal distinctions, with specific focus on coronal consonants. Therefore, tongue tip and jaw positions are compared for the German coronal consonants /s, , t, d, n, l/, that is, consonants having the same active articulators (apical/laminal) but differing in manner of articulation. In order to test the stability of articulatory positions for each of these coronal consonants, a natural perturbation paradigm was introduced by recording two levels of vocal effort: comfortable, and loud without shouting. Tongue and jaw movements of five speakers of German were recorded by means of EMMA during /aCa/ sequences. By analyzing the tongue tip and jaw positions and their spatial variability we found that (1) the jaws contribution to these consonants varies with manner of articulation, and (2) for all coronal consonants the positions are stable across loudness conditions except for those of the nasal. Results are discussed with respect to the tasks of the jaw, and the possible articulatory adjustments that may accompany louder speech.

Syllabification in Moroccan Arabic : evidence from patterns of temporal stability in articulation

Competing proposals on the syllabification of initial consonants in Moroccan Arabic are evaluated using a combination of experimental and modelling techniques. The proposed model interprets an input syllable structure as a set of articulatory landmarks coordinated in time. This enables the simulation of temporal patterns associated with the input syllable structure under different noise conditions. Patterns of stability between landmarks simulated by the model are matched to patterns in data collected with Electromagnetic Articulometry experiments. The results implicate a heterosyllabic parse of initial clusters so that strings like /sbu/ comprise two syllables, [s.bu]. Beyond this specific result for Moroccan Arabic, the model reveals the range of validity of certain stability-based indexes of syllable structure and generates predictions that allow evaluation of a syllabic parse even when stability-based heuristics break down. Overall, the paper provides support for the broad hypothesis that syllable structure is reflected in patterns of temporal stability and contributes analytical tools to evaluate competing theories on the basis of these patterns.

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 /∫/ 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 /∫/, 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.

Articulatory analysis of the German vowel system

It is undoubtedly the case that what, purely for the sake of convenience, we will refer to as the tense-lax opposition has been the most debated feature of the German vowel system, both in the phonetic and phonological literature. We will not attempt to cover this debate here, but for reviews from various points of view see for example, Mooshammer (1998), Becker (1998), Sendlmeier (1985), Ramers (1988), Wood (1975 ab), Fischer-Jørgensen (1985). From the point of view of our principal interest in the kinematics of speech, one of the most intriguing aspects of the debate – more so than the rather static approach of the quantity vs. quality discussion – has come from the long series of phonological papers that capture the distinction in more dynamic terms (as Anders Löfqvist once said, “the movement is the message”), particularly in the link between vowel and following consonant. Thus terms such as syllable-cut ( Silbenschnitt ) arose, with smoothly cut ( sanft geschnittene ) syllables containing tense vowels, and abruptly cut ( scharf geschnittene ) syllables containing lax vowels (cf. Sievers 1901, and especially the more recent formulations of Vennemann 1991, embedding the opposition firmly in a prosodic theory of syllable structure). The corresponding terminology favoured by Trubetzkoy (1939), following the approach of Jespersen (1913), would be loose contact ( loser Anschluss ) for tense vowels, and close contact (fester Anschluss ) for lax vowels. The terms used throughout the 20 th century for this very consistent intuition clearly suggest that characteristic movement differences should be observable, but attempts to find a phonetic substrate were – equally consistently – inconclusive (e.g Fischer-Jørgensen/Jørgensen 1969, but see Spiekermann 2000 and this volume). In this contribution we review the results of articulatory investigations of German vowel production that have been carried out in our laboratories over the last few years. Given that our emphasis is on articulatory analysis we have not attempted to review acoustic analyses of the German vowel system. In addition, while, in the light of the above remarks, the question of the so-called tense-lax opposition will be very much to the fore in this paper, we would like to emphasize that in our opinion it is only possible to understand how the speech motor system copes with the task of realizing such an opposition – i.e what spatial and tem-

Dynamic invariance in the phonetic expression of syllable structure : a case study of Moroccan Arabic consonant clusters*

We asked whether invariant phonetic indices for syllable structure can be identified in a language where word-initial consonant clusters, regardless of their sonority profile, are claimed to be parsed heterosyllabically. Four speakers of Moroccan Arabic were recorded, using Electromagnetic Articulography. Pursuing previous work, we employed temporal diagnostics for syllable structure, consisting of static correspondences between any given phonological organisation and its presumed phonetic indices. We show that such correspondences offer only a partial understanding of the relation between syllabic organisation and continuous indices of that organisation. We analyse the failure of the diagnostics and put forth a new approach in which different phonological organisations prescribe different ways in which phonetic indices change as phonetic parameters are scaled. The main finding is that invariance is found in these patterns of change, rather than in static correspondences between phonological constructs and fixed values for their phonetic indices.

Acoustic and respiratory evidence for utterance planning in German

Abstract This study investigates prosodic planning in a reading task in German. We analyse how the utterance length and syntactic complexity of an upcoming sentence affect two acoustic parameters (pause duration and the initial fundamental frequency peak) and two respiratory parameters (inhalation depth and inhalation duration). Two experiments were carried out. In the first experiment, data for twelve native speakers of German were recorded. They read sentences varying in length (short, long) and syntactic complexity (simple, complex). Data were analysed on the basis of the four phonetic parameters. Pause duration, inhalation depth and inhalation duration showed significant differences with respect to sentence length, but not to syntactic complexity. The initial f0 peak was not influenced by variations in length or syntactic complexity. In the second experiment it was hypothesized that the initial f0 peak is only sensitive to length manipulations of the first constituent. Twenty speakers were recorded reading utterances varying in the length of the first (short, medium, long) and last syntactic constituent (short, long). Results for the initial f0 peak confirmed our hypothesis. It is concluded that the breathing parameters and pause duration are global parameters for planning of the upcoming sentence whereas the height of the fundamental frequency peak is a more local measure sensitive to the length of the first constituent.

Prosodic and segmental effects on EPG contact patterns of word-initial German clusters

This study investigates the effects of segmental composition and prosodic variation, namely boundary strength and lexical stress, on the production of word-initial clusters in German. The internal structure of the clusters /kl, kn, ks, sk/ has been analyzed by means of EPG recordings from seven speakers of German. Derived temporal and spatial parameters indicate that /kn/ is consistently produced with a lag between the consonants and /kl/ with considerable overlap. This categorical difference is also stable across stress and boundary conditions and is attributed to manner-based and perceptual recoverability constraints. No clear pattern emerges for /sk/ and /ks/. Therefore, stability of temporal organization across prosodic conditions is only tested for /kl/ and /kn/. Temporally, boundary level affects the duration of the adjacent consonant and the overlap within the clusters /kn/ and /kl/, whereas spatially /k/ is affected only in /kn/ but not in /kl/. Stress effects are not restricted to the nucleus but also affect the internal organization of the clusters. The interplay between segmental and prosodic timing effects indicates that the internal structure of clusters shows linguistically crucial and highly constrained timing patterns which can only vary within certain limits.

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.

Electromagnetic articulography as a tool in the study of lingual coarticulation

Two recent papers [Schonle et al., Biomedizinische Technik 34, 126–130 (1989) and Shao et al., J. Acoust. Soc. Am. Suppl. 1 86, S115 (1989)] have evaluated a commercially available electromagnetic system for articulatory measurements, the articulograph AG‐100. The present investigation includes some complementary methodological studies followed by an analysis of vowel‐to‐vowel coarticulation in German speakers. Within the first area, discussion focuses on the problems encountered and the solutions chosen in adapting the system for large‐scale data collection, relevant topics including sample rates, noise, extension of the standard calibration procedures, detection of corrupted data by means of appropriate control tasks, and synchronization with audio recordings. Preliminary work in the second area suggested that the spatial magnitude of vocalic carryover effects in VCV sequences exceeded that of anticipatory effects at the midpoint of the intervening consonants. This will be reviewed in the light of two r...