Consonants In Initial Position Research Articles

Voice onset time of plosive consonants in initial position in badidni dialect

Phoneticians have presented several ways and theories for knowing the features and characteristics of plosive consonants. Acoustic ways are ones that languages’ plosive consonants are determined by them. In the last 60 years VOT was widely used as an acoustic parameter by phoneticians for comparing voicing contrast and determining the categories and features of plosive consonants as an acceptable way. Until now it’s not known that plosive consonants are determined in badini dialect according to the VOT parameter. This study is an attempt to what extent we can benefit from the mentioned parameter for specifying voicing contrast distinction, voicing categories and their properties and features. For this purpose the two plosive consonants /b, p/ are used as a stimulus of this investigation in the initial 6 monosyllabic words in the environment of the two vowels /ɑ æ,/. The collected data are taken from (20) badini dialect speakers. It’s assumed that voicing contrast, VOT values and the categories of plosive (voiced and voiceless) consonants are different in baddini dialect. Depending on procedures and statistical analysis tests it concludes that; VOT is formed in three ways and three separate values. This study consists of five sections; the first section is the introduction, the second one is theoretical framework, in the third section the procedures of doing this study are shown, statistical results and discussing them are mentioned in the fourth section and the conclusions of the study are shown in the fifth section.

Wavelet based sub-band parameters for classification of unaspirated Hindi stop consonants in initial position of CV syllables

This paper proposes a new feature extraction technique using wavelet based sub-band parameters (WBSP) for classification of unaspirated Hindi stop consonants. The extracted acoustic parameters show marked deviation from the values reported for English and other languages, Hindi having distinguishing manner based features. Since acoustic parameters are difficult to be extracted automatically for speech recognition. Mel Frequency Cepstral Coefficient (MFCC) based features are usually used. MFCC are based on short time Fourier transform (STFT) which assumes the speech signal to be stationary over a short period. This assumption is specifically violated in case of stop consonants. In WBSP, from acoustic study, the features derived from CV syllables have different weighting factors with the middle segment having the maximum. The wavelet transform has been applied to splitting of signal into 8 sub-bands of different bandwidths and the variation of energy in different sub-bands is also taken into account. WBSP gives improved classification scores. The number of filters used (8) for feature extraction in WBSP is less compared to the number (24) used for MFCC. Its classification performance has been compared with four other techniques using linear classifier. Further, Principal components analysis (PCA) has also been applied to reduce dimensionality.

Could Phonemic Awareness Instruction Be (Part of) the Answer for Young EFL Learners? A Report on the Early Literacy Project in Malaysia

The Curriculum Specifications for English, set out in the Ministry of Education Malaysia syllabus for Year 1, calls for instruction in phonemic awareness (PA; see definition below) as part of the acquisition of word recognition skills. Students are expected to be able to learn individual letters of the alphabet and their sounds; read aloud consonants in initial positions and vowels in both initial and medial positions; and compare words for similar sounds (Curriculum Development Centre, 2006, p. 20). In some parts of rural Malaysia, where English is functionally a foreign language, and being learned by many Year 1 pupils as a third or even fourth language, these objectives may be overly optimistic. Rural students in national schools are instructed via the medium of Bahasa Malaysia (Malaysia's official language, also known as Malay), and asked in Year 1 to master its alphabet and sound system, alongside English. Year 1 students in rural Chinese- or Tamil-medium schools are busy acquiring the script and sound system of one of those languages, of Bahasa Malaysia, and of English as well. For children from orang asli (aboriginal) or one of the many other linguistic backgrounds in the country, this task is complicated even further. The ongoing frustrations of both teachers and teacher-trainers in these rural parts of the country led some to wonder whether direct instruction in phonemic awareness might assist young Malaysian learners in the acquisition of phonemic awareness in English.

Phonetic skills and vocabulary size in late talkers: Concurrent and predictive relationships

AbstractPhonetic skills and vocabulary size were investigated in 37 toddlers (24 to 31 months) identified with specific expressive language impairment and 20 comparison toddlers matched on age, SES, and nonverbal ability. The use of consonants was highly consistent across two contexts: 20 minutes of structured testing and 5 minutes of free play. The comparison children produced almost triple the number of consonant types and five times as many consonant tokens as the late talkers. However, the most frequently present consonants were similar across groups, indicating delayed rather than deviant phonetic development in the late talkers. The late talkers used a much higher proportion of their consonants in initial position than did the normally developing toddlers. Consonant types and tokens were significantly related to reported vocabulary size on Rescorla's (1989) Language Development Survey. No significant predictive relationship was found between either phonetic repertoire or vocabulary size at intake and age 3 language outcome. However, age 3 MLU and IPSyn scores were significantly predicted by age-normed severity of expressive delay at intake (Reynell Expressive z score), with more delayed children showing poorer outcomes.

Perception of syllable-initial English stops by native Korean listeners

Duration of attenuation in the region of the first formant (F1 cutback) and relative level of aspiration energy are known to be significant acoustic cues used to distinguish voiced from voiceless English stop consonants in initial position. This experiment was designed to test whether Korean listeners distinguish English stops on the same bases as native English listeners. In an identification task, 72 stimuli from six continua ranging perceptually from /da/ to /ta/ were presented to 12 Korean and 12 English subjects. Stimuli were synthesized using a parallel formant synthesizer and varied in duration of F1 cutback (5–82 ns in 7-ms steps), relative amplitude of prevocalic aspiration energy, and fundamental frequency (100, 125, and 150 Hz) of vocalic energy. Longer F1-cutback durations and greater aspiration intensity both significantly increased the proportion of voiceless /ta/ responses for both Korean and English subjects. Only Korean subjects labeled more stops as voiceless when fundamental frequency was higher. [Work supported by NIDCD grant DC-00719 and NSF grant DBS-9258482.]

Release burst masking effects for temporal order identification

Nearly three decades ago, Hirsh [J. Acoust. Soc. Am. 31, 759–761 (1959)] found that the threshold for identification of temporal order of onset is significantly longer than the threshold for detection of onset asynchrony, and proposed that the order identification threshold might serve as a basis for the contrast between voiced and unvoiced aspirated stop consonants in initial position. In the last decade, a number of researchers have argued that temporal order identification threshold does not play a significant role in voicing contrast. One basis for this argument against a phonetic perception role is that the 15- to 20-ms range of typical order identification thresholds for simple stimuli are significantly shorter than VOT boundaries typical for synthetic stop consonants which include an initial release burst. The current research investigated the possible contribution of an initial noise burst analog as a masking stimulus. The initial noise burst shifts temporal order identification thresholds to significantly longer onset asynchronies which are equivalent in magnitude to VOT voicing contrast boundaries.

An aerodynamic study of Korean stop consonants: measurements and modeling.

Measurements were made of intraoral air pressure and oral flow of ten native speakers uttering word pairs contrasting Korean fortis and lenis voiceless stop consonants in initial position. The production of fortis stops was found to be characterized by a higher intraoral pressure before release, yet a lower oral flow after release, than corresponding lenis stops. Possible reasons for this difference were explored with the use of a computer implemented aerodynamic model, giving an output of air pressure and flow. Input parameters were adjusted in accordance with known or hypothesized variations in glottal area function, vocal tract wall tension, respiratory muscle force, and supraglottal cavity volume, as given in the literature. In addition to the previously known differences in glottal area, it is inferred from the results of the modeling experiment that fortis stops are produced with greater vocal tract wall tension than lenis stops. Speaker-specific production strategies such as larynx lowering and heightened subglottal pressure during fortis stops and differences noted between word pairs are also discussed.

Perception of voice onset time: A cross language study of American English and Danish

This paper examines the relationship between the production and perception of the voicing distinction for American English and Danish stop consonants in initial position. In a comparison of the production of /p/ and /k/ for the two languages the Danish stops were found to have longer aspiration. It was therefore hypothesized that perceptually, Danish listeners would have a later cross-over point than American listeners. This was tested in a labelling experiment, using computer-edited, naturally produced stimuli. The aspiration was shortened from right to left to produce a series of stimuli ranging in VOT from +10 to +70 msec of the syllables pi, pu, ki, and ku. The listening tests showed a statistically significant difference in the expected direction for the labial stimuli but not for the velars. This may be due to the stimulus range which proved to be less appropriate for Danish listeners than for American listeners.

Stop consonant discrimination based on human audition

A system for discrimination of stop consonants has been designed on the basis of studies of auditory physiology and psychophysics. The system consists of a one-third octave filter bank as an approximation to auditory tuning curves, a bank of high speed, wide dynamic range envelope detectors, a logarithmic amplifier, and a digital computer for analysis and display. Features, chosen on the basis of psychophysical experiments, are then abstracted, and fed to a discriminant analysis program which decides on the most probable phomene. Discrimination accuracy of about 77% for stop consonants in initial position has been achieved, with a 15-speaker data set.

Letter: Is it VOT or a first-formant transition detector?

Discussion of voicing as a distinctive property of English stop consonants in initial position has centered on the measure of ’’VOT,’’ the time of onset of laryngeal signal relative to the noise pulse generated by the stop release, but it has been shown that listeners’ selection of ‖b,d,g‖ vs ‖p,t,k‖ responses to synthetic stop+vowel stimuli is not determined entirely by VOT. Significant effects have been reported to depend on the behavior of the first formant (F1) frequency immediately following voice onset, and on this basis it has been suggested that a ’’feature detector’’ responsive to a rapidly shifting F1 better explains the infant’s discrimination of the two stop categories than some mechanism which measures VOT directly. The relative importance of VOT as against the presence versus absence of F1 frequency shift after voice onset is assayed in several synthesis experiments in which VOT and F1 configurations are systematically varied. Labeling data obtained indicate that varying VOT regularly effects a significant change in listeners’ judgments, and that varying F1 has some effect too, but this latter variation is neither necessary nor sufficient generally to shift judgments decisively from one stop category to the other. The data further suggest that the presence of an F1 rising transition after voice onset serves as a voiced-stop cue not so much because of its dynamic aspect, but simply because its onset frequency is low, i.e., at a value appropriate to a closed or almost closed state of the oral cavity. Subject Classification: 70.30, 70.20, 70.70.

Synthesis of Stop Consonants in Initial Position

A complete set of rules is described for the production of English stop consonants in initial position with a terminal analog speech synthesizer. The five-pole series-connected synthesizer is simulated on a medium-sized general purpose computer, and has several novel features. Frication spectra are generated by controlling a five-pole fricative tract so that frication poles are continuous with the poles of the segment that follows, but several of these poles may be effectively canceled by zeros depending on the place of articulation. An aspiration noise source having a flat spectrum is used to produce a good approximation to natural aspiration when the noise is inserted in place of the voicing source. Rules to be described govern the characteristics of (1) a short duration of frication at the release of a stop; (2) aspiration in a voiceless stop; and (3) formant transitions into the following segment. These rules have been used to generate a randomized list of 90 CV nonsense syllables consisting of the stops /p,b,t,d,k,g/ followed by 15 English vowels. A panel of naïve listeners can identify more than 95% of these consonants. [This work was supported in part by the National Institutes of Health and in part by the U. S. Air Force Cambridge Research Laboratories, Office of Aerospace Research.]

Significant features in the perception of (Hindi) consonants.

Twenty-nine consonants in the initial position and 31 consonants in the final position of CVC syllables were studied for perceptual confusions. The error matrices for consonants in initial and final positions showed significant differences in the response. A quantitative procedure was adopted to ascertain which features were most significant for listeners, and whether or not these were similar in the initial and final positions. The amount of information transmitted in bits per stimulus was calculated for all features and for each feature separately. The data indicated that the rank order of the features is not similar in the two positions. A comparison with observations made by earlier workers and with a recent work in this laboratory on intelligibility of consonants in clipped speech provided further evidence to show that the initial and final vowel transitions play different rôles in the recognition of consonants.