Pan European Voice Conference - PEVOC 11

The Pan European VOice Conference (PEVOC) was born in 1995 and therefore in 2015 it celebrates the 20th anniversary of its establishment: an important milestone that clearly expresses the strength and interest of the scientific community for the topics of this conference. The most significant themes of PEVOC are singing pedagogy and art, but also occupational voice disorders, neurology, rehabilitation, image and video analysis. PEVOC takes place in different European cities every two years (www.pevoc.org). The PEVOC 11 conference includes a symposium of the Collegium Medicorum Theatri (www.comet collegium.com

Ihmisen äänentuoton analysointi käänteissuodatuksen, suurnopeuskuvauksen ja elektroglottografian avulla

Human voice production was studied using three methods: inverse filtering, digital high-speed imaging of the vocal folds, and electroglottography. The primary goal was to evaluate an inverse filtering method by comparing inverse filtered glottal flow estimates with information obtained by the other methods. More detailed examination of the human voice source behavior was also included in the work. Material from two experiments was analyzed in this study. The data of the first experiment consisted of simultaneous recordings of acoustic speech signal, electroglottogram, and high-speed imaging acquired during sustained vowel phonations. Inverse filtered glottal flow estimates were compared with glottal area waveforms derived from the image material by calculating pulse shape parameters from the signals. The material of the second experiment included recordings of acoustic speech signal and electroglottogram during phonations of sustained vowels. This material was utilized for the analysis of the opening phase and the closing phase of vocal fold vibration. The evaluated inverse filtering method was found to produce mostly reasonable estimates of glottal flow. However, the parameters of the system have to be set appropriately, which requires experience on inverse filtering and speech production. The flow estimates often showed a two-stage opening phase with two instants of rapid increase in the flow derivative. The instant of glottal opening detected in the electroglottogram was often found to coincide with an increase in the flow derivative. The instant of minimum flow derivative was found to occur mostly during the last quarter of the closing phase and it was shown to precede the closing peak of the differentiated electroglottogram.Ihmisen puheentuottoa tutkittiin kolmella menetelmällä: käänteissuodatuksella, äänihuulten digitaalisella suurnopeuskuvauksella ja elektroglottografialla. Päätavoitteena oli tarkastella erään käänteissuodatusmenetelmän toimintaa vertailemalla näillä menetelmillä saatua informaatiota äänihuulten värähtelystä. Lisäksi tutkittiin tarkemmin eräitä äänilähteen käyttäytymisen yksityiskohtia. Tutkimuksessa analysoitiin aineistoa kahdesta koejärjestelystä. Ensimmäisessä kokeessa tallennettiin samanaikaisesti äänisignaali, elektroglottogrammi ja suurnopeuskuvamateriaalia äänihuulista koehenkilöiden tuottaessa pitkiä vokaaleita. Käänteissuodatuksella saaduista glottisvirtausestimaateista sekä kuvamateriaalin ilmaisemasta ääniraon pinta-alavaihtelusta laskettiin pulssiparametreja, joiden avulla vertailtiin virtauksen ja ääniraon pinta-alan käyttäytymistä. Toisen koejärjestelyn aineisto koostui äänisignaalista ja elektroglottogrammista, jotka oli tallennettu vokaaliääntöjen aikana. Tämän materiaalin perusteella analysoitiin ääniraon avautumis- ja sulkeutumisvaihetta. Tarkastellun käänteissuodatusmenetelmän todettiin tuottavan enimmäkseen luotettavia virtausestimaatteja edellyttäen, että menetelmän parametrit asetetaan tarkoituksenmukaisesti, mikä vaatii käyttäjältä kokemusta käänteissuodatuksesta ja ihmisen puheentuotosta. Glottisvirtauksen avautumisvaiheen havaittiin olevan useissa virtausestimaateissa kaksivaiheinen siten, että virtauksen kasvu voimistuu nopeasti kahdessa kohdassa sulkeutumisen ja maksimivirtauksen välillä. Virtauksen kasvun todettiin usein voimistuvan elektroglottogrammista tunnistetun ääniraon avautumishetken lähellä. Virtauksen derivaatan minimikohdan havaittiin sijoittuvan enimmäkseen virtauksen sulkeutumisvaiheen viimeiseen neljännekseen, ja sen osoitettiin esiintyvän ennen elektroglottogrammin derivaatan minimikohtaa

The glottalic consonants of Hausa.

This thesis is concerned with the examination of the glottalic consonants of Hausa, a Chadic language spoken in northern Nigeria, Niger, Cameroon, Togo and Ghana. The glottalic consonants constitute a set of phonemes in the language whose historical and phonetic properties merit further investigation. The study is laid out in three parts. Part one (Chapters 1, 2 and 3) is the historical section. Here, a general overview of the Hausa language is given. Also discussed are several specific points made by pioneers of the genetic classification of Chadic within Afroasiatic and the reconstruction of glottalic consonants in both Chadic and Afroasiatic. The discussion here is not new but presents a summary of the literature. Hausa native words that have glottalic consonants are compared with possible cognates from other related Chadic languages from West, Central and East branches of Chadic and also from other Afroasiatic languages. Part two (Chapters 4 and 5) of the study concerns the investigation of phonation types in general. Chapter 4 gives a short account of the larynx, the mechanism of the vocal fold vibration and classification of phonation types. Chapter 5 is devoted to a review of instrumental techniques used in voice measurement. Part three (Chapter 6, the instrumental section) presents and discusses the results of a detailed electro- laryngographic analysis of the activity of the behaviour of the vocal folds in the production of the glottalic consonants and their non-glottalic counterparts as observed in the speech of educated native speakers of the language. The chapter begins with a review of the literature reporting early instrumental and non-instrumental studies of the segmental phonemes of the language. This is followed by a description of the techniques used to record, display and annotate both speech pressure and laryngographic waveforms. Both qualitative and quantitative analysis of the waveforms are presented. The most important parameter in the quantitative analysis is estimated open quotient (OQ) derived from the Lx waveforms measurements of Fundamental Frequency, duration and Voice Onset Time are also given. The chapter concludes by presenting the results of the experiment: 1 OQ increases in anticipation of plain voiceless consonants, and is relatively high at the consonantal release; 2 OQ decreases in anticipation of laryngealized consonants including the glottal stop (for most speakers) and less sharply for the ejectives; 3 OQ remains approximately at the speaker's modal value for the plain voiced consonants; 4 The laryngealized segments tend to lower pitch at the left of the consonant; and 5 They also tend to be longer than their plain counterparts

A novel framework for high-quality voice source analysis and synthesis

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.The analysis, parameterization and modeling of voice source estimates obtained via inverse filtering of recorded speech are some of the most challenging areas of speech processing owing to the fact humans produce a wide range of voice source realizations and that the voice source estimates commonly contain artifacts due to the non-linear time-varying source-filter coupling. Currently, the most widely adopted representation of voice source signal is Liljencrants-Fant's (LF) model which was developed in late 1985. Due to the overly simplistic interpretation of voice source dynamics, LF model can not represent the fine temporal structure of glottal flow derivative realizations nor can it carry the sufficient spectral richness to facilitate a truly natural sounding speech synthesis. In this thesis we have introduced Characteristic Glottal Pulse Waveform Parameterization and Modeling (CGPWPM) which constitutes an entirely novel framework for voice source analysis, parameterization and reconstruction. In comparative evaluation of CGPWPM and LF model we have demonstrated that the proposed method is able to preserve higher levels of speaker dependant information from the voice source estimates and realize a more natural sounding speech synthesis. In general, we have shown that CGPWPM-based speech synthesis rates highly on the scale of absolute perceptual acceptability and that speech signals are faithfully reconstructed on consistent basis, across speakers, gender. We have applied CGPWPM to voice quality profiling and text-independent voice quality conversion method. The proposed voice conversion method is able to achieve the desired perceptual effects and the modified speech remained as natural sounding and intelligible as natural speech. In this thesis, we have also developed an optimal wavelet thresholding strategy for voice source signals which is able to suppress aspiration noise and still retain both the slow and the rapid variations in the voice source estimate