Human-machine communication for educational systems design

This book contains the papers presented at the NATO Advanced Study Institute (ASI) on the Basics of man-machine communication for the design of educational systems, held August 16-26, 1993, in Eindhoven, The Netherland

On marked declaratives, exclamatives, and discourse particles in Castilian Spanish

This book provides a new perspective on prosodically marked declaratives, wh-exclamatives, and discourse particles in the Madrid variety of Spanish. It argues that some marked forms differ from unmarked forms in that they encode modal evaluations of the at-issue meaning. Two epistemic evaluations that can be shown to be encoded by intonation in Spanish are linguistically encoded surprise, or mirativity, and obviousness. An empirical investigation via an audio-enhanced production experiment finds that mirativity and obviousness are associated with distinct intonational features under constant focus scope, with stances of (dis)agreement showing an impact on obvious declaratives. Wh-exclamatives are found not to differ significantly in intonational marking from neutral declaratives, showing that they need not be miratives. Moreover, we find that intonational marking on different discourse particles in natural dialogue correlates with their meaning contribution without being fully determined by it. In part, these findings quantitatively confirm previous qualitative findings on the meaning of intonational configurations in Madrid Spanish. But they also add new insights on the role intonation plays in the negotiation of commitments and expectations between interlocutors

Exploring the influence of suprasegmental features of speech on rater judgements of intelligibility

A thesis submitted to the University of Bedfordshire in partial fulfilment of the requirements for the degree of Doctor of PhilosophyThe importance of suprasegmental features of speech to pronunciation proficiency is well known, yet limited research has been undertaken to identify how raters attend to suprasegmental features in the English-language speaking test encounter. Currently, such features appear to be underrepresented in language learning frameworks and are not always satisfactorily incorporated into the analytical rating scales that are used by major language testing organisations. This thesis explores the influence of lexical stress, rhythm and intonation on rater decision making in order to provide insight into their proper place in rating scales and frameworks. Data were collected from 30 raters, half of whom were experienced professional raters and half of whom lacked rater training and a background in language learning or teaching. The raters were initially asked to score 12 test taker performances using a 9-point intelligibility scale. The performances were taken from the long turn of Cambridge English Main Suite exams and were selected on the basis of the inclusion of a range of notable suprasegmental features. Following scoring, the raters took part in a stimulated recall procedure to report the features that influenced their decisions. The resulting scores were quantitatively analysed using many-facet Rasch measurement analysis. Transcriptions of the verbal reports were analysed using qualitative methods. Finally, an integrated analysis of the quantitative and qualitative data was undertaken to develop a series of suprasegmental rating scale descriptors. The results showed that experienced raters do appear to attend to specific suprasegmental features in a reliable way, and that their decisions have a great deal in common with the way non-experienced raters regard such features. This indicates that stress, rhythm, and intonation may be somewhat underrepresented on current speaking proficiency scales and frameworks. The study concludes with the presentation of a series of suprasegmental rating scale descriptors

A Study of Accomodation of Prosodic and Temporal Features in Spoken Dialogues in View of Speech Technology Applications

Inter-speaker accommodation is a well-known property of human speech and human interaction in general. Broadly it refers to the behavioural patterns of two (or more) interactants and the effect of the (verbal and non-verbal) behaviour of each to that of the other(s). Implementation of thisbehavior in spoken dialogue systems is desirable as an improvement on the naturalness of humanmachine interaction. However, traditional qualitative descriptions of accommodation phenomena do not provide sufficient information for such an implementation. Therefore, a quantitativedescription of inter-speaker accommodation is required. This thesis proposes a methodology of monitoring accommodation during a human or humancomputer dialogue, which utilizes a moving average filter over sequential frames for each speaker. These frames are time-aligned across the speakers, hence the name Time Aligned Moving Average (TAMA). Analysis of spontaneous human dialogue recordings by means of the TAMA methodology reveals ubiquitous accommodation of prosodic features (pitch, intensity and speech rate) across interlocutors, and allows for statistical (time series) modeling of the behaviour, in a way which is meaningful for implementation in spoken dialogue system (SDS) environments.In addition, a novel dialogue representation is proposed that provides an additional point of view to that of TAMA in monitoring accommodation of temporal features (inter-speaker pause length and overlap frequency). This representation is a percentage turn distribution of individual speakercontributions in a dialogue frame which circumvents strict attribution of speaker-turns, by considering both interlocutors as synchronously active. Both TAMA and turn distribution metrics indicate that correlation of average pause length and overlap frequency between speakers can be attributed to accommodation (a debated issue), and point to possible improvements in SDS “turntaking” behaviour. Although the findings of the prosodic and temporal analyses can directly inform SDS implementations, further work is required in order to describe inter-speaker accommodation sufficiently, as well as to develop an adequate testing platform for evaluating the magnitude ofperceived improvement in human-machine interaction. Therefore, this thesis constitutes a first step towards a convincingly useful implementation of accommodation in spoken dialogue systems

Acoustic Measures of the Singing Voice in Secondary School Students

Descriptions of voice quality in vocal and choral music often rely on subjective terminology, which may be perceived differently between individuals. As access to software used in acoustic measurement becomes more widespread and affordable, music educators can potentially combine traditional descriptive terminology with objective acoustic descriptors and data, which may improve both teaching and singing. The secondary school choral music educator has specific challenges, in that they teach students who experience drastic physical and acoustic changes of the voice as they grow from children to adults. The purpose of this study was to objectively analyze various acoustic characteristics of the singing voice in secondary school students. In this study, secondary school students (N = 157) from three different schools who were enrolled in choir (n = 89) or instrumental music classes (n = 68) recorded voice samples singing five vowels, /i/, /e/, /a/, /o/, and /u/. Research questions investigated (a) descriptive statistics for vibrato rate, vibrato extent, singing power ratio, and amplitude differences between specific harmonic pairs; (b) differences in vibrato rate and extent between students enrolled in choir and students not enrolled in choir; (c) between-subjects and within-subjects comparisons in singing power ratio (SPR) between singers based on choir enrollment and voice part for five different vowel productions; and (d) between-subjects and within-subjects comparisons for differences in amplitude between specific harmonics between singers based on choir enrollment and voice part for five different vowel productions. Vibrato rate (M = 4.58 Hz, SD = 1.45 Hz ), vibrato extent (M = 1.45% or 25 cents, SD = 0.86% or 15 cents), and SPR (M = 24.67 dB, SD = 10 dB), and various amplitude differences were not different between students enrolled in choir and students not enrolled in choir. There were significant within-subjects differences for singers by vowel, as well as significant within-subjects interactions for vowel and voice part with SPR and amplitude differences between harmonic pairs. There were also significant differences between voice parts for amplitude difference between harmonic pairs. Implications for choral music educators and suggestions for further research based on these findings were discussed in Chapter 5