Articulation Model Research Articles

Citizen Willingness to Assist as Volunteers in the Provision of Local Public Goods: A Case Study of Volunteer Firemen in 70 West German Cities

Abstract. Volunteer activity, from one perspective, that of the theory of public choice, provides an outlet for the articulation of demand for public goods. To analyze its role in that function, a theoretical model is constructed which incorporates the social, benevolence and demand articulation elements of volunteerism into a single utility function. The utility function is based on the economics of clubs and the economics of charity views of utility. The theoretical model shows how the rational individual weighs the benefits and costs of volunteerism and relates this behavior to the rational voter model of demand articulation. The model is then empirically tested, using data for volunteer fire companies in 70 West German cities. The empirical results show that to the extent volunteer activities are considered to be a form of demand articulation, they are consistent with the rational voter hypothesis.

On Certain Evidence for the Feature [Grave

Supposed evidence for acoustic assimilations attributable to the feature [grave], presented in Hyman 1973 and Vago 1976, is shown to be evidence merely of deficient modeling of articulation in the SPE articulatory-feature system-rather than, as Hyman and Vago assume, proof for the acoustic basis of the processes they cite. Straightforward articulatory explanations are available for all the evidence adduced, but they are not expressible in the SPE framework. The necessary refinements of such a system of articulatory description are shown to require more than adjustments of the feature inventory.*

Don't Hold Them Back: A Critique and Guide to New High School-College Articulation Models. By Baird W. Whit-lock. New York: College Entrance Examination Board, 1978

Don't Hold Them Back: A Critique and Guide to New High School-College Articulation Models. By Baird W. Whit-lock. New York: College Entrance Examination Board, 1978

Automatic generation of voiceless excitation in a vocal cord-vocal tract speech synthesizer

A speech synthesis technique is described which incorporates acoustic models for sound propagation in a tube with yielding walls, turbulent noise generation at locations of constricted volume flow in the vocal tract, and the self-oscillatory properties of the vocal cord source. This formulation frees the experimenter from a traditional limitation, namely, the assumption of linear separability of sound source and resonant system. As a consequence, new opportunities accrue for building realistic physiological characteristics into the synthesizer. These built-in characteristics represent information that need not be overtly supplied to control the synthesizer. The system is used to synthesize test syllables from controls which are stylized models of articulation and connected speech from controls automatically derived from printed text. The synthesis technique demonstrates the feasibility of generating all speech sounds (voiced, unvoiced, nasal) from a common set of physiologically based control parameters, as the human does.

A model of articulatory dynamics and control

A model of human articulation is described whose spatial and dynamic characteristics closely match those of natural speech. The model includes a controller that embodies enough articulatory "motor skill" to produce, from discrete phonetic strings, properly timed sequences of articulatory movements. Together with programs for dictionary searching and rules for duration and other phonetic variables, the model can produce reasonably acceptable synthetic speech from ordinary English text.

Lip and jaw coarticulation for the phoneme (ae).

The timing and coarticulation of jaw lowering and lip retraction was investigated. Meaningful sentences containing sequences of up to four consonants preceding the vowel /æ/ were constructed, and high speed cinefluorographic films were made of four subjects speaking all sequences at normal production rates and effort levels. Curve fitting indicated that the lips and jaw do not behave as second-order mechanical systems responding to a step-function of muscle driving force. Lip retraction was a poor estimate of lip spreading, being small in amount, and variable in starting points. The jaw never achieved target values, and a majority of lip targets were undershot. Articulator target positions based on sustained, isolated phoneme productions are probably not realistic. Jaw displacement and less consistently, lip retraction, extended over two and, in several cases, three consonants preceding /æ/. This result might have been extended had the /s/ phone not been contradictory to one or both gestures. Extensive incoordination of lips and jaw in achieving target positions simultaneously and in starting at like time points was observed. The data were related to several models of articulation.

Acoustical description of syllabic nuclei: an interpretation in terms of a dynamic model of articulation.

Measurements of formant frequencies throughout the vocalic portions of a number of phonemically symmetric consonant-vowel-consonant utterances have been performed using spectrum-matching techniques implemented on a digital computer. The contours representing the first two formants as a function of time are described in terms of several parameters, including initial and final frequencies, midpoint frequencies, durations, and measures of curvature. The data illustrate the manner in which each of these parameters is influenced by the features of the vowel and by place of articulation of the adjacent consonants. The results provide evidence that diffuse tense vowels in English are characterized by diphthongal asymmetric articulatory motions, whereas nondiffuse vowels are not, and that the influence of the consonantal environment on the articulation of the vowel is greater for lax vowels than for tense vowels. Some general statements are made concerning the extent to which contiguous vowels and consonants influence each other's production.

Spectrographic Study of Vowel Reduction

Measurements of formant frequencies and duration are reported for 8 Swedish vowels uttered by a male talker in three consonantal environments under varying timing conditions. An exponential function is used to describe the extent to which formant frequencies in the vowels reach their target values as a function of vowel-segment duration. A target is specified by the asymptotic values of the first two formant frequencies of the vowel and is independent of consonantal context and duration. It is thus an invariant attribute of the vowel. The results suggest an interpretation in terms of a simple dynamic model of vowel articulation.

Analysis of Acoustic Speech Signals into Articulatory Parameters

An analysis technique is discussed whereby speech spectra are compared with spectra generated by a computer-simulated model of articulation. In this model, a spectrum is determined by specifying as input parameters a vocal-tract area function (or a simplified configurational description) and the source spectral envelope and location. The input parameters are adjusted to obtain a “spectral match” between the internally generated spectrum and the speech spectrum, thereby specifying the articulatory parameters that correspond to the given speech spectrum. Data relating to matches from several classes of speech sounds are presented. Questions pertaining to the uniqueness and applicability of the parameters obtained by this procedure are discussed, with particular reference to descriptions of vocal-tract dynamics. The possibility of using parameters derived by this technique to control a dynamic vocal-tract analog synthesizer is also considered. [This work was supported in part by the U. S. Army, the U. S. Air Force Office of Scientific Research, and the U. S. Office of Naval Research; in part by the U. S. Air Force (Electronic Systems Division) under Contract AF 19(604)-6102; in part by the National Science Foundation (Grant G-16526); and in part by the National Institutes of Health (Grant MH-04737-02).