Jan Volín

The effect of word-initial glottalization on word monitoring in Slovak speakers of English

Abstract The study investigates the impact of glottal elements before word-initial vowels on the speed of processing of the phrases taken from natural continuous speech. In many languages a word beginning with a vowel can be preceded by a glottal stop or a short period of creaky voice. However, languages differ in the extent of use and functions of this glottalization: it may be used to mark the word boundary, for instance, or to add special prominence to the word. The aim of the experiment was to find out whether the presence of the glottal element can influence reaction times in a word-monitoring paradigm. Users of different languages - Slovak and Czech learners of English, as well as native speakers of English - were participating in perception testing so that the influence of the mother tongue could be determined. The results confirm the effect of both glottalization and the L1 of the listeners. In addition, a significant effect of test item manipulations was found. Although the phrases with added or deleted glottal stops displayed no obvious acoustic artefacts, they produced longer reaction times than items with naturally present or absent glottalizations. We believe that this finding underlines the importance of inherent stress patterns, whose alterations lead to the increase in processing load.

On the Extension of the Formal Prosody Model for TTS

The formal prosody grammar used for TTS focuses mainly on the description of final prosodic words in phrases/sentences which characterize a special prosodic phenomenon representing a certain communication function within the language system. This paper introduces an extension of the prosody model which also takes into account the importance and distinction of the first prosodic words in the prosodic phrases. This phenomenon can not change the semantic interpretation of the phrase, but for higher naturalness, the beginnings of the prosodic phrases differ from subsequent words and should be, based on the phonetic background, dealt with separately.

Speech Melody Properties in English, Czech and Czech English: Reference and Interference

Abstract Two major objectives were set for the present study: to provide reference data for the description of Czech and English F0 contours, and to investigate the limits of the ‘interference hypothesis’ on Czech English data. Altogether, the production of 40 speakers in 2392 breath-group F0 contours was analyzed. The speech of 32 professional speakers of English and Czech provides reference values for various acoustic correlates of pitch level, pitch span and downtrend gradient. These values were subsequently used as a benchmark for a confirmation of the interference hypothesis through comparison with a further sample of 8 non-professional speakers of English and Czech-accented English. The native English speakers of both genders produced significantly higher pitch level indicators, wider pitch span and a steeper downtrend gradient than the reference native speakers of Czech. Although the pitch level of the Czech-accented material lies in between the two reference groups, the pitch span of this group is the narrowest, which indicates that factors of foreign-accentedness other than simply interference are in effect.

Spectral Characteristics of Schwa in Czech Accented English

Abstract The English central mid lax vowel (i.e., schwa) often contributes considerably to the sound differences between native and non-native speech. Many foreign speakers of English fail to reduce certain underlying vowels to schwa, which, on the suprasegmental level of description, affects the perceived rhythm of their speech. However, the problem of capturing quantitatively the differences between native and non-native schwa poses difficulties that, to this day, have been tackled only partially. We offer a technique of measurement in the acoustic domain that has not been probed properly as yet: the distribution of acoustic energy in the vowel spectrum. Our results show that spectral slope features measured in weak vowels discriminate between Czech and British speakers of English quite reliably. Moreover, the measurements of formant bandwidths turned out to be useful for the same task, albeit less direct

P-centres in natural disyllabic Czech words in a large-scale speech-metronome synchronization experiment

Abstract The difficulty of pinpointing a specific event within words that would correspond to the p-centre is well known. The current experiment, investigating the position of p-centres in Czech, aims to replicate the findings from English and several other languages, and substantially increase the range of phonotactic types and the number of participants. In a speech-metronome synchronization task, 24 subjects pronounced a set of 37 natural disyllabic Czech words of differing complexity at two metronome rates. The beginning of the first vowel (V1) and the moment of the fastest increase in energy within the first syllable were the most consistent synchronization points, but the p-centre occurred earlier than at the V1 initial boundary. Synchronization intervals were significantly influenced by the complexity of the syllabic onset: the p-centre was positioned earlier (further from the V1) as more consonants were included in the onset. The effects of vowel length and final coda were also present, but weaker. In addition, various aspects of human musicality were found to correlate with the ability of speakers to synchronize their articulations with an isochronous auditory sequence.

ACOUSTIC CORRELATES OF WORD STRESS AS A CUE TO ACCENT STRENGTH

Abstract Due to the clear interference of their mother tongue prosody, many Czech learners produce their English with a conspicuous foreign accent. The goal of the present study is to investigate the acoustic cues that differentiate stressed and unstressed syllabic nuclei and identify individual details concerning their contribution to the specific sound of Czech English. Speech production of sixteen female non-professional Czech and British speakers was analysed with the sounds segmented on a word and phone level and with both canonical and actual stress positions manually marked. Prior to analyses the strength of the foreign accent was assessed in a perception test. Subsequently, stressed and unstressed vowels were measured with respect to their duration, amplitude, fundamental frequency and spectral slope. Our results show that, in general, Czech speakers use much less acoustic marking of stress than the British subjects. The difference is most prominent in the domains of fundamental frequency and amplitude. The Czech speakers also deviate from the canonical placement of stress, shifting it frequently to the first syllable. On the other hand, they seem to approximate the needed durational difference quite successfully. These outcomes support the concept of language interference since they correspond with the existing linguistic knowledge about Czech and English word stress. The study adds specific details concerning the extent of this interference in four acoustic dimensions.

THE IMPACT OF RHYTHMIC DISTORTIONS IN SPEECH ON PERSONALITY ASSESSMENT

Abstract The perennial question as to how perceived otherness in speech projects into listener assessment of one’s personality has been systematically investigated within the field of foreign accentedness, vocal communication of affective states and vocal stereotyping. In the present study, we aimed at exploring non-native listeners’ capacity to respond to differences in natural and modified native speech, particularly whether the manipulation of temporal structure in both stressed and unstressed syllables gives rise to any changes in the perception of the speaker’s personality. The respondents’ intuitive judgements were captured in the domain of the ‘nervousness category’ taken from the five-factor model of personality. Our results indicate an effect of temporal modifications on the listeners’ judgements. Analysis of variance for repeated measures confirmed a highly significant shift of personality evaluations towards the undesired traits (e.g., nervousness, anxiety, querulousness). Several interesting interactions with the semantic contents of the utterances and with the intrinsic qualities of the speakers’ voices were also found. We argue that the effects of accented speech go beyond conscious willingness to accept “otherness” and suggest a method for studying them.

\(\hbox {F}_0\) Post-Stress Rise Trends Consideration in Unit Selection TTS

In spoken Czech language, the stress and post-stress syllables in human speech are usually characterized by an increase in fundamental frequency \(\hbox {F}_0\) (except for phrase-final stress groups). In unit selection text-to-speech systems, where no contour of \(\hbox {F}_0\) is generated to be followed, however, the \(\hbox {F}_0\) behaviour is usually tended very vaguely. The paper presents an experiment of making the unit selection TTS to follow the trends of fundamental frequency rise in synthesized speech to achieve higher naturalness and overall quality of speech synthesis itself.

Acoustic correlates of prosodic dimensions in younger and older speakers of Czech

The present study reports phonetic data applicable for diagnostic purposes in voice related pathologies. However, apart from purely physiological concern, linguistic considerations are also acknowledged since the speech material consists of a continuous spoken text. Three age groups of speakers were recorded (young, middle-aged and old adults), each represented by 15 men and 15 women (n = 90). Several measures of fundamental frequency, together with variation in intensity and speech tempo were captured. An appreciably innovative metric, Cumulative Slope Index (CSI), was successfully employed to capture F0 variability in utterances. The results confirm differences between the age groups, but also between men and women, and contribute the normative mapping of the Czech population.

Pitch range of intonation contours in English Czech

Pitch range is believed to code important information that is indispensable for correct decoding of spoken messages. Previous research found differences in pitch variation across languages like English, French, Bulgarian, Polish, Czech and German. In addition, differences in pitch range of foreign-accented and native speech were found in various types of speech material. In the present study a sample of sixteen English and American men and women produced recordings of spoken texts consisting of eight paragraphs taken from Czech news broadcasts. Manually corrected F0 tracks provided a possibility to extract four measures of F0 distributional dispersion in order to map global intonational habits of Anglophone learners of Czech as a foreign language. The extracted values were compared with reference values from earlier studies. The results in all four measures indicate that foreign accented Czech is spoken with a pitch range that is narrower than that of English and often even narrower than that of native Czech. Considering results of similar, albeit smaller, studies done earlier, we would attribute our findings to implicit uncertainty in the use of the foreign language, rather than to overcompensation.