Clear Vowel Research Articles

The Role of Text To Speech Assistive Technology to Improve Reading Ability in E-Learning for ADHD Students

This study aims to determine the role of text to speech assistive technology on the reading ability of ADHD students in learning using e-learning. The ability of ADHD students who have impulsive and hyperactive behavior shows that students who are diagnosed will have difficulty focusing on one thing as a result of coordination functions and emotional responses that affect learning abilities, especially in reading. To improve reading skills, the use of assistive text to speech technology is needed by students during e-learning. The purpose of this study was to determine the role of text to speech assistive technology to improve the reading ability of ADHD students in reading spelling of words, with a clear voice and straightforward word emphasis. The method used in this study is Single Subject Research (SSR) using the ABA technique. Instruments to determine the level of reading ability of ADHD students are observation and documentation. The results showed that the role of text to speech assistive technology to improve reading skills in e-learning for ADHD students made progress in spelling words and with clear vowels and straightforward word emphasis. It can be concluded that the role of text to speech assistive technology to improve reading skills in e-learning for ADHD students is highly recommended to be applied in every e-learning lesson. It can be concluded that the role of text to speech assistive technology to improve reading skills in e-learning for ADHD students is highly recommended to be applied in every e-learning lesson.

Vowels of four-year-old children with cerebral palsy in Mandarin-learning environment

Characteristics of vowel productions of children with cerebral palsy (CP) were investigated with data from two 4-year-old children with CP and two typically-developing (TD) children in Mandarin-learning environment. Clear vowel productions from picture naming and natural conversation in three 50-minute audio recordings of each child were transcribed and analyzed. Seven parameters were examined: vowel duration of /a/, F2 slope in transition of CV sequence, cumulative change of F2 for vowel /a/, degree of nasalization in oral vowel (A1-P1), percent of jitter, percent of shimmer, and the signal to noise ratio (SNR). Major findings are: (1) The CP group showed shorter vowel duration of /a/; (2) TD group has larger F2 slope in CV transition; (3) No obvious differences were found between TD and CP groups in cumulative change of F2 for vowel /a/, degree of nasalization (A1-P1), and voice perturbation (percent of jitter, percent of shimmer, and SNR). Further study with more participants and with careful data selection can verify findings of this study in search for valid parameters to characterize vowel production of children with CP.

Vowel Mutability in Print in English and Spanish

Studies of vowel mutability have shown that it is easier to change a nonword (e.g., /tibl/) into a real word by changing a vowel (/tebl/) than by changing a consonant (/fibl/). All previous studies have used auditory materials, suggesting that the effect is a spoken language phenomenon. We conducted two studies with print materials, one in English and one in Spanish. Both showed clear vowel mutability effects, suggesting that vowel mutability is a more a general phenomenon. Vowel mutability is also shown to be one of many phenomena in which vowels and consonants show asymmetrical effects. Implications for models of auditory and visual word recognition are discussed.

Effect of dialect on identification and severity of speech impairment in Indigenous Australian children

This study investigated the effect of dialectal difference on identification and rating of severity of speech impairment in children from Indigenous Australian backgrounds. The speech of 15 Indigenous Australian children identified by their parents/caregivers and teachers as having ‘difficulty talking and making speech sounds’ was assessed using the Diagnostic Evaluation of Articulation and Phonology. Fourteen children were identified with speech impairment on the Diagnostic Evaluation of Articulation and Phonology using Standard Australian English (AusE) as the target pronunciation; whereas 13 were identified using Australian Aboriginal English (AAE) as the target. There was a statistically significant decrease in seven children’s severity classification and a statistically significant increase in all children’s percentage of consonants, vowels and phonemes correct when comparing AAE with AusE. Features of AAE used by the children included /h/ insertion and deletion, primary stress on the first syllable and diphthongs alternating with short clear vowels. It is important that speech-language pathologists consider children’s dialect as one component of culturally and linguistically appropriate services.

人工神経回路モデルと声道物理モデルを用いた母音模倣モデルに基づく音素獲得シミュレーション

This paper proposes a continuous vowel imitation system that explains the process of phoneme acquisition by infants from the dynamical systems perspective. Almost existing models concerning this process dealt with discrete phoneme sequences. Human infants, however, have no knowledge of phoneme innately. They perceive speech sounds as continuous acoustic signals. The imitation target of this study is continuous acoustic signals including unknown numbers and kinds of phonemes. The key ideas of the model are (1) the use of a physical vocal tract model called the Maeda model for embodying the motor theory of speech perception, (2) the use of a dynamical system called the Recurrent Neural Network with Parametric Bias (RNNPB) trained with both dynamics of the acoustic signals and articulatory movements of the Maeda model, and (3) the segmenting method of a temporal sequence using the prediction error of the RNNPB model. The experiments of our model demonstrated following results: (a) the self-organization of the vowel structure into attractors of RNNPB model, (b) the improvement of vowel imitation using movement of the Maeda model, and (c) the generation of clear vowels based on the bubbling process trained with a few random utterances. These results suggest that our model reflects the process of phoneme acquisition.

Talker Differences in Clear and Conversational Speech: Acoustic Characteristics of Vowels

To determine the specific acoustic changes that underlie improved vowel intelligibility in clear speech. Seven acoustic metrics were measured for conversational and clear vowels produced by 12 talkers-6 who previously were found (S. H. Ferguson, 2004) to produce a large clear speech vowel intelligibility effect for listeners with normal hearing identifying vowels in background noise (the big benefit talkers), and 6 who produced no clear speech vowel intelligibility benefit (the no benefit talkers). For vowel duration and for certain measures of the overall acoustic vowel space, the change from conversational to clear speech was significantly greater for big benefit talkers than for no benefit talkers. For measures of formant dynamics, in contrast, the clear speech effect was similar for the 2 groups. These results suggest that acoustic vowel space expansion and large vowel duration increases improve vowel intelligibility. In contrast, changing the dynamic characteristics of vowels seems not to contribute to improved clear speech vowel intelligibility. However, talker variability suggested that improved vowel intelligibility can be achieved using a variety of clear speech strategies, including some apparently not measured here.

Acoustic correlates of breathy and clear vowels: the case of Khmer

This study investigates acoustic correlates of the putative breathy and clear phonation type contrast in a dialect of Khmer (Cambodian) spoken in Chanthaburi Province, Thailand. The goal is to determine whether this Khmer dialect still preserves this historical contrast. Out of seven acoustic parameters measured, four, namely *H 1− *H 2 , *H 1−A 1 , *H 1− *A 3 , and vowel RMS amplitude successfully distinguished between breathy and clear vowels, with *H 1− *H 2 measured at the beginning of the vowel being the most robust cue. However, the use of these cues varied from speaker to speaker. The *H 1− *H 2 measurement obtained from male speakers’ production suggested that the contrast being realized may be that of a tense versus lax voice rather than a breathy versus clear voice. It is concluded that the historical breathy and clear phonation distinction in Khmer is preserved among female speakers, but this distinction may be disappearing or have become a tense versus lax distinction among male speakers.

Perception of word-final /t/, /d/, /s/, and /z/ by beginning Spanish-speaking learners of English

Previous research has indicated that speakers of Spanish learning English have problems perceiving and producing the word-final /t/–/d/ contrast [Flege, 1992]. In this study we examined whether beginning learners of English from Latin America could distinguish word-final voicing and manner contrasts among /d/, /t/, /s/, and /z/ when produced in three different vowel contexts by two speakers. As expected, subjects had difficulty correctly discriminating the voicing distinction in both stops and fricatives. On average, performance was poorer on /t/–/d/ than /s/–/z/. Subjects had no difficulty distinguishing voiced or voiceless consonants differing in manner. There was a clear vowel effect; performance was poorer on average for voicing contrast in the high front vowel context than for low central and high back contexts, although there were individual differences. There was also a strong speaker effect; subjects more easily identified the /d/–/t/ contrast of the male speaker, who had longer closure durations and stronger release bursts than those of the female speaker.

Acoustic correlates of breathy and clear phonation types

Only a decade ago were types of phonation shown to have a phonological function in a language. Several languages spoken in Southeast Asia were claimed to have contrastive phonation type (i.e., clear, breathy and creaky) in their vowel systems. Several different techniques were employed to investigate this phenomenon. These included examining the physical appearance of the acoustic wave form, inverse-filtering, measuring the difference between amplitude of the first and the second harmonics (H1–H2), or between the first harmonic and the most prominent harmonic in the F1 and F3 regions (H1–A1, H1–A3), harmonic-to-noise ratio (HNR) as well as some aerodynamic techniques. This present study proposes to investigate the breathy versus clear phonation contrast phenomenon in Chong, a Mon-Khmer language spoken in Thailand using several of the above-mentioned techniques. Preliminary analysis suggested that only the H1–H2 values obtained for breathy vowels were greater than for clear vowels. The nonsignificant difference between breathy and clear vowels in Chong in other dimensions will be discussed in relation to the question of whether or not Chong should be classified as a phonation-type language.

Surveying auditory space using vowel formant data

Recent research has suggested that vowel category learning and the perceptual magnet effect are the natural consequences of auditory neural map formation [F. H. Guenther and M. N. Gjaja, J. Acoust. Soc. Am. 100, 1111–1121 (1996)]. As these effects are language specific, the organization of the perceptual map crucially is dependent on the input received during learning. Guenther and Gjaja implemented a working model of a self-organizing neural map to show that, given input from Gaussian distributions around vowel category centers, unsupervised training leads to a warping of the perceptual space toward the category centers. This work replicates Guenther and Gjaja’s results and provides a more realistic test of the model by using real vowel formant data instead of idealized distributions. Single and multiple male talker vowel data were used to train auditory neural maps. Single-talker simulations resulted in map organization similar to Guenther and Gjaja’s results. However, no clear vowel category clusters emerged in the multiple-talker simulations. [Work supported by NSF Graduate Fellowship and NIH FIRST Award R29-DC01645-06.]