Finding the Most Uniform Changes in Vowel Polygon Caused by Psychological Stress

Using vowel polygons, exactly their parameters, is chosen as the criterion for achievement of differences between normal state of speaker and relevant speech under real psychological stress. All results were experimentally obtained by created software for vowel polygon analysis applied on ExamStress database. Selected 6 methods based on cross-correlation of different features were classified by the coefficient of variation and for each individual vowel polygon, the efficiency coefficient marking the most significant and uniform differences between stressed and normal speech were calculated. As the best method for observing generated differences resulted method considered mean of cross correlation values received for difference area value with vector length and angle parameter couples. Generally, best results for stress detection are achieved by vowel triangles created by /i/-/o/-/u/ and /a/-/i/-/o/ vowel triangles in formant planes containing the fifth formant F5 combined with other formants

Stress recognition from speech signal

Předložená disertační práce se zabývá vývojem algoritmů pro detekci stresu z řečového signálu. Inovativnost této práce se vyznačuje dvěma typy analýzy řečového signálu, a to za použití samohláskových polygonů a analýzy hlasivkových pulsů. Obě tyto základní analýzy mohou sloužit k detekci stresu v řečovém signálu, což bylo dokázáno sérií provedených experimentů. Nejlepších výsledků bylo dosaženo pomocí tzv. Closing-To-Opening phase ratio příznaku v Top-To-Bottom kritériu v kombinaci s vhodným klasifikátorem. Detekce stresu založená na této analýze může být definována jako jazykově i fonémově nezávislá, což bylo rovněž dokázáno získanými výsledky, které dosahují v některých případech až 95% úspěšnosti. Všechny experimenty byly provedeny na vytvořené české databázi obsahující reálný stres, a některé experimenty byly také provedeny pro anglickou stresovou databázi SUSAS.Presented doctoral thesis is focused on development of algorithms for psychological stress detection in speech signal. The novelty of this thesis aims on two different analysis of the speech signal- the analysis of vowel polygons and the analysis of glottal pulses. By performed experiments, the doctoral thesis uncovers the possible usage of both fundamental analyses for psychological stress detection in speech. The analysis of glottal pulses in amplitude domain according to Top-To-Bottom criterion seems to be as the most effective with the combination of properly chosen classifier, which can be defined as language and phoneme independent way to stress recognition. All experiments were performed on developed Czech real stress database and some observations were also made on English database SUSAS. The variety of possibly effective ways of stress recognition in speech leads to approach very high recognition accuracy of their combination, or of their possible usage for detection of other speaker’s state, which has to be further tested and verified by appropriate databases.

An exploration of the rhythm of Malay

In recent years there has been a surge of interest in speech rhythm. However we still lack a clear understanding of the nature of rhythm and rhythmic differences across languages. Various metrics have been proposed as means for measuring rhythm on the phonetic level and making typological comparisons between languages (Ramus et al, 1999; Grabe & Low, 2002; Dellwo, 2006) but the debate is ongoing on the extent to which these metrics capture the rhythmic basis of speech (Arvaniti, 2009; Fletcher, in press). Furthermore, cross linguistic studies of rhythm have covered a relatively small number of languages and research on previously unclassified languages is necessary to fully develop the typology of rhythm. This study examines the rhythmic features of Malay, for which, to date, relatively little work has been carried out on aspects rhythm and timing. The material for the analysis comprised 10 sentences produced by 20 speakers of standard Malay (10 males and 10 females). The recordings were first analysed using rhythm metrics proposed by Ramus et. al (1999) and Grabe & Low (2002). These metrics (∆C, %V, rPVI, nPVI) are based on durational measurements of vocalic and consonantal intervals. The results indicated that Malay clustered with other so-called syllable-timed languages like French and Spanish on the basis of all metrics. However, underlying the overall findings for these metrics there was a large degree of variability in values across speakers and sentences, with some speakers having values in the range typical of stressed-timed languages like English. Further analysis has been carried out in light of Fletcher’s (in press) argument that measurements based on duration do not wholly reflect speech rhythm as there are many other factors that can influence values of consonantal and vocalic intervals, and Arvaniti’s (2009) suggestion that other features of speech should also be considered in description of rhythm to discover what contributes to listeners’ perception of regularity. Spectrographic analysis of the Malay recordings brought to light two parameters that displayed consistency and regularity for all speakers and sentences: the duration of individual vowels and the duration of intervals between intensity minima. This poster presents the results of these investigations and points to connections between the features which seem to be consistently regulated in the timing of Malay connected speech and aspects of Malay phonology. The results are discussed in light of current debate on the descriptions of rhythm

Models and analysis of vocal emissions for biomedical applications

This book of Proceedings collects the papers presented at the 3rd International Workshop on Models and Analysis of Vocal Emissions for Biomedical Applications, MAVEBA 2003, held 10-12 December 2003, Firenze, Italy. The workshop is organised every two years, and aims to stimulate contacts between specialists active in research and industrial developments, in the area of voice analysis for biomedical applications. The scope of the Workshop includes all aspects of voice modelling and analysis, ranging from fundamental research to all kinds of biomedical applications and related established and advanced technologies

The phonological development of adult Japanese learners of English : a longitudinal study of perception and production.

SIGLEAvailable from British Library Document Supply Centre-DSC:DXN042757 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Manipulation of Auditory Feedback in Individuals with Normal Hearing and Hearing Loss

Auditory feedback, the hearing of one’s own voice, plays an important role in the detection of speech errors and the regulation of speech production. The limited auditory cues available with a hearing loss can reduce the ability of individuals with hearing loss to use their auditory feedback. Hearing aids are a common assistive device that amplifies inaudible sounds. Hearing aids can also change auditory feedback through digital signal processing, such as frequency lowering. Frequency lowering moves high frequency information of an incoming auditory stimulus into a lower frequency region where audibility may be better. This can change how speech sounds are perceived. For example, the high frequency information of /s/ is moved closer to the lower frequency area of /ʃ/. As well, real-time signal processing in a laboratory setting can also manipulate various aspects of speech cues, such as intensity and vowel formants. These changes in auditory feedback may result in changes in speech production as the speech motor control system may perceive these perturbations as speech errors. A series of experiments were carried out to examine changes in speech production as a result of perturbations in the auditory feedback in individuals with normal hearing and hearing loss. Intensity and vowel formant perturbations were conducted using real-time signal processing in the laboratory. As well, changes in speech production were measured using auditory feedback that was processed with frequency lowering technology in hearing aids. Acoustic characteristics of intensity of vowels, sibilant fricatives, and first and second formants were analyzed. The results showed that the speech motor control system is sensitive to changes in auditory feedback because perturbations in auditory feedback can result in changes in speech production. However, speech production is not completely controlled by auditory feedback and other feedback systems, such as the somatosensory system, are also involved. An impairment of the auditory system can reduce the ability of the speech motor control system to use auditory feedback in the detection of speech errors, even when aided with hearing aids. Effects of frequency lowering in hearing aids on speech production depend on the parameters used and acclimatization time

Speech Communication

Contains reports on five research projects.National Institutes of Health (Grant 5 RO1 NS04332-12)National Institutes of Health (Grant HD05168-04)U.S. Navy Office of Naval Research (Contract N00014-67-A-0204-0069)Joint Services Electronics Program (Contract DAAB07-74-C-0630)National Science Foundation (Grant SOC74-22167