20 research outputs found
Italian speakers learn lexical stress of German morphologically complex words
No full textItalian speakers tend to stress the second component of German morphologically complex words such as compounds and prefix verbs even if the first component is lexically stressed. To improve their prosodic phrasing an automatic pronunciation teaching method was developed based on auditory feedback of prosodically corrected utterances in the learners’ own voices. Basically, the method copies contours of F0, local speech rate, and intensity from reference utterances of a German native speaker to the learners’ speech signals. It also adds emphasis to the stress position in order to help the learners better recognise the correct pronunciation and identify their errors. A perception test with German native speakers revealed that manipulated utterances significantly better reflect lexical stress than the corresponding original utterances. Thus, two groups of Italian learners of German were provided with different feedback during a training session, one group with manipulated utterances in their individual voices and the other with correctly pronounced original utterances in the teacher’s voice. Afterwards, both groups produced the same sentences again and German native speakers judged the resulting utterances. Resynthesised stimuli, especially with emphasised stress, were found to be a more effective feedback than natural stimuli to learn the correct stress position. Since resynthesis was obtained without previous segmentation of the learners’ speech signals, this technology could be effectively included in Computer Assisted Language Learning software
H.R. Pfitzinger Towards functional modelling of relationships between the acoustics and perception of vowels
No full textThis paper summarizes our research efforts in functional modelling of the relationship between the acoustic properties of vowels and perceived vowel quality. Our model is trained on 164 short steady-state stimuli. We measured F1, F2, and additionally F0 since the effect of F0 on perceptual vowel height is evident. 40 phonetically skilled subjects judged vowel quality using the Cardinal Vowel diagram. The main focus is on refining the model and describing its transformation properties between the F1/F2 formant chart and the Cardinal Vowel diagram. An evaluation of the model based on 48 additional vowels showed the generalizability of the model and confirmed that it predicts perceived vowel quality with sufficient accuracy. 1
The /i/-/a/-/u/-ness of Spoken Vowels
No full textThis paper investigates acoustic, phonetic, and phonological representations of spoken vowels. For this purpose four experiments have been conducted. First, by drawing the analogy between the spectral energy distribution of vowels and the vowel space concept of Dependency Phonology, we achieve a new phonologically motivated vowel quality representation of spoken vowels which we name the /i/-/a/-/u/-ness. As a second step, it is shown that the extension of this approach is connected with the work of Pols, van der Kamp & Plomp 1969 [1] who, among other things, predicted formant frequencies from the spectral energy distribution of vowels. Third, the vowel quality relating to the IPA vowel diagram is derived directly from the spectral energy distribution. Finally, we compare this method with a formant and fundamental frequency based approach introduced by Pfitzinger 2003 [2]. While both the /i/-/a/-/u/-ness of vowels as well as the perceived vowel quality prediction are quite robust and therefore useful for both signal pre-processing and vowel quality research, the formant prediction achieved the lowest accuracy for the mapping to the IPA vowel diagram
Text-based and Signal-based Prediction of Break Indices and Pause Durations
No full textThe relation between symbolic and signal features of prosodic
boundaries is experimentally studied using prediction methods.
Text-based break index prediction turns out to be fairly good,
but signal-based prediction and pause duration prediction perform worse. A possible reason is that random signal feature
variations, as usually produced by humans, are hard to predict
Unsupervised Speech Morphing between Utterances of any Speakers
No full textA new approach to speech morphing is presented which avoids the extraction of fundamental and formant frequencies as well as the detection of phone or syllable boundaries. All prominent spectral and temporal features of the source and target utterances are automatically related and interpolated. The method consists of three main parts: LPC-based source-filter decomposition, separate interpolation, and composition of the morphed speech signal. The paper focuses on the alignment and interpolation problems on three speech signal layers: the timing structure on a phone- and syllable-level, the shape of the frequency spectrum including formants and other spectral properties, and the micro-timing of the source signal. Particularly, the source signal alignment and interpolation is described since it is most crucial for the resulting quality of the modified speech signal. The new morphing procedure was applied to utterances taken from the freely available CMU ARCTIC speech corpus and assessed by a perceptual MOS experiment. Preliminar
Influence of Differences between Inverse Filtering Techniques On The Residual Signal of Speech
No full textTowards functional modelling of relationships between the acoustics and perception of vowels
No full textThis paper summarizes our research efforts in functional modelling of the relationship between the acoustic properties of vowels and perceived vowel quality. Our model is trained on 164 short steady-state stimuli. We measured F1, F2, and additionally F0 since the effect of F0 on perceptual vowel height is evident. 40 phonetically skilled subjects judged vowel quality using the Cardinal Vowel diagram. The main focus is on refining the model and describing its transformation properties between the F1/F2 formant chart and the Cardinal Vowel diagram. An evaluation of the model based on 48 additional vowels showed the generalizability of the model and confirmed that it predicts perceived vowel quality with sufficient accuracy
Two approaches to speech rate estimation
No full textABSTRACT – This paper introduces two approaches to speech rate estimation: one is based on automatic syllable detection and the other on automatic phone segmentation. For evaluation of both approaches we used manually segmented syllables and phones as a reference. Although the used segment detectors are not perfect it is possible to automatically estimate the local rate of phones and the local rate of syllables reliably. We argue that neither the rate of phones nor the rate of syllables suffices for estimating actual speech rate
Reducing Segmental Duration Variation by Local Speech Rate Normalization of Large Spoken Language Resources
No full textWe developed a time-domain normalization procedure which uses a speech signal and its corresponding speech rate contour as an input, and produces the normalized speech signal. Then we normalized the speech rate of a large spoken language resource of German read speech. We compared the resulting segment durations with the original durations using several three-way ANOVAs with phone type and speaker as independent variables, since we assume that segment duration variation is determined by segment type (intrinsic duration), by the speaker (speech rate, sociolect, ideolect, dialect, speech production variation), and by linguistic effects (context, syllable structure, accent, and stress). One important result of the statistical analysis was, that the influence of the speaker on segment duration variation decreased dramatically (factor 0.54 for vowels, factor 0.29 for consonants) when normalizing speech rate, despite the fact that sociolect, ideolect, and dialect remained almost unchanged. Since the interaction between the independent variables speaker and phone type remained constantly, the hypothesis arises, that this interaction contains most of the speaker-specific information
Years Of Phondat-II: A Reassessment
No full textIn this paper we conduct an evaluation as well as a reassessment of the PhonDatII spoken language resource. 10 years after the record of PhonDatII it is time to summarize and to look into its future. At present, the corpus comprises 39612 manually labelled phone tokens and 15083 syllable tokens of read German utterances. We describe the corpus in detail, and then we present a new method to evaluate segmentation boundaries. Finally, we ask the question as to how we can refine the PhonDatII database for the future. The mean phone duration results of this study, which are based on a corrected and extended version of the PhonDatII corpus, are in correspondence with earlier research. Consequently, the actual size of this spoken language resource seems to be sufficient for generalization of results on the segmental level
