Articulation Of Fricatives Research Articles

Temporal, spectral and amplitude characteristics of the Greek fricative /s/ in hearing-impaired and normal-hearing speech

ABSTRACT Fricatives, and especially sibilants, are very frequently misarticulated by speakers with hearing loss. Misarticulations can result in phonemic contrast weakening or loss, compromising intelligibility. The present study focuses on the examination of acoustic characteristics of the Greek alveolar fricative /s/, an articulatorily demanding sound, produced by young adult speakers with profound hearing impairment and with normal hearing. An array of variables was examined using mixed-effects and random forest models aiming to assess the effectiveness of various measures in differentiating hearing-impaired and normal-hearing /s/ production. Significant differences were found in spectral and amplitude measures, but not in temporal measures. In hearing-impaired speech, spectral slope and RMS amplitude had significantly lower values, indicating a more distributed spectrum, suggestive of decreased flow velocity through the fricative constriction. Also, a trend for concentration of energy at lower frequencies was observed suggesting more posterior fricative articulation than normal. Moreover, measures capturing the variation of frequency and amplitude over time revealed different patterns of sibilance development across time than normal, denoting the production of a less well-formed or less sibilant /s/ by speakers with hearing impairment. The investigation of contextual effects on /s/ in hearing-impaired speech showed increased spectral variance, negative skewness and lower kurtosis in the labial (rounded) context /u/ in relation to the nonlabial contexts /i/ and /a/, indicating a more diffuse, less compact spectrum with concentration at high frequencies. Findings are discussed in relation to previous literature on fricative production by speakers with hearing impairment and normal hearing in Greek and other languages.

Estimation of place of articulation of fricatives from spectral features

Estimation of place of articulation of fricatives from spectral features

A Cross-Sectional Age Group Study of Coarticulatory Resistance: The Case of Late-Acquired Voiceless Fricatives in English.

As a class, fricatives are more "resistant" to consonant-vowel coarticulation than other English sounds. This study investigates the relative coarticulatory resistance of /θ, s, ʃ/ in child and adult speech to better understand the acquisition of individuated speech sounds. Ten 5-year-old children, seven 8-year-old children, and nine college-age adults produced [əFV] sequences in carrier phrases, where F was /θ/, /s/, or /ʃ/ and V was /æ/, /i/, or /u/. In Experiment 1, coarticulation was perceptually indexed: 65 adults predicted the target stressed vowel based on forward-gated audiovisual speech samples for a subset of four speakers from each age group. In Experiment 2, dynamic spectral measures of the /əFV/ sequences were analyzed using smoothing spline analysis of variance to again test for vowel effects on fricative articulation across age groups. The perceptual results indicated that fricatives blocked vowel-vowel coarticulation across speaker age groups. Contrary to expectation, vowels were most accurately predicted when F was /s/ and not when it was /ʃ/ or /θ/ across age groups. Acoustic results indicated the expected biomechanically motivated /ʃ/ > /s/ > /θ/ coarticulatory resistance hierarchy in adults' speech. By contrast, /ʃ/ > /s/ were similarly influenced by context in 8-year-olds' speech, and the results from 5-year-olds' speech suggested an influence of order of acquisition in that /θ/ was surprisingly resistant to coarticulation. The study results are taken to suggest that a temporal constraint on fricative articulation interacts with biomechanical constraints during development to influence patterns of coarticulation in school-age children's speech.

THE PHONETICS OF NASAL‐FRICATIVE SEQUENCES IN LATIN

AbstractInscriptional material and descriptions by grammarians from the classical period indicate that vowels were regularly lengthened before‐ns‐and‐nf‐sequences in Latin, e.g.,cōnsulandīnfēlīx. Additionally, nasals were often lost in this environment. The nasal deletion was driven by articulatory mechanisms, namely the difficulty of articulating a nasal directly before an anterior fricative. Diverting air to the nasal cavity reduces oral air pressure; however, the articulation of fricatives requires high air pressure at the point of constriction in order for frication of the air stream to occur. Speakers of Latin reduced the articulatory burden of these sequences by reducing nasal air flow, and over time the nasals were deleted. Preceding vowels were then lengthened to compensate for the lost mora associated with the deleted nasal. The articulatory explanation for the development of nasal‐fricative sequences will be supported by the facts of sociolinguistics: the reintroduction of nasals in‐ns‐and‐nf‐sequences is associated with elite speech and formal contexts, where the coarticulation between these two segments can be closely monitored by speakers.

Strategy of Velopharyngeal Closure Function in Articulation of Fricatives

Strategy of Velopharyngeal Closure Function in Articulation of Fricatives

Voz y habla de los niños con síndrome de deleción de 22q11

The 22q11 deletion syndrome (S22q11) is a genetic disorder caused by the loss of a fragment of the chromosome 22. The clinical manifestations associated with the syndrome are diverse, including learning difficulties and alterations in voice, speech and language. However, to date we have not found any study that evaluates these aspects in the Spanish population with S22q11. We evaluate the voice and speech of a sample of 10 boys and 7 girls, aged 3 years and 3 months to 13 years and 9 months old (mean age: 9,4 ± 3,5 years old) with S22q11, with voice recordings and a phonological and phonetic evaluation. Also, semistructured type interview is administered to parents. Most children of our series, both male and female, with S22q11 have a deeper voice than expected by gender and age, except for male children over 12 years. In terms of intensity, all of them are within the parameters of normality in spontaneous conversation. Almost all of them showed alterations in voice quality, mainly due to hypernasality. Regarding the speech, there are major difficulties in the articulation of fricatives, affricates and vibrant rhotic consonant clusters + /r/. Likewise, children, especially the youngest ones, make use of glottal stops to replace consonants. In the studied sample, most of the children with S22q11 have specific voice and speech alterations.

Articulation or phonology? Evidence from longitudinal error data

ABSTRACTChildren’s speech difficulties can be motor (phone misarticulation) or linguistic (impaired knowledge of phonological contrasts and constraints). These two difficulties sometimes co-occur. This paper reports longitudinal data from the Early Language in Victoria Study (ELVS) at 4 and 7 years of age. Of 1494 participants, 93 made non-age appropriate speech errors on standardised assessments at 4 years, and were able to be reassessed at 7 years. At 4 years, 85% of these children only made phonological errors, 14% made both articulation and phonological errors and one child only made articulation errors (a lateral lisp). In total, 8 of 13 children making both articulation and phonological errors at 4 years had resolved by 7 years. Unexpectedly, eight children who had demonstrated articulation of fricatives at 4 years, acquired distorted production of ≥ 50% of occurrences of/s, z/ by 7 years. In total, then, 22 children (24% of children with speech difficulties) made articulatory errors at one or both assessments. Case data for all children are presented. Theoretical and clinical implications are considered.

PERILAKU FONEM DALAM BAHASA ARAB DAN IMPLIKASINYA TERHADAP MAKNA

This research aims to study phoneme’s behaviour on Arabic words and to discover the relation between voice and its meaning. Phoneme, as the smallest contrastive linguistic unit, has a huge influence on bringing a change of meaning. The preference of certain phoneme on a word may produce certain meaning inside it. Therefore, a singel word with different phonemes produces different meaning. This research based on library research, a research proceed by gathering some facts from various books, articles, and other literatures related to the subject. This research combines semantical approach and phonological approach with analytic description method. This research finds that Arabic words use certain phoneme to express certain meaning; phonemes with heavy articulations are often used to express serious meanings, and phonemss with light articulations are often used to express trivial meanings. It is also found that phoneme articulation has many patterns, such as plosive articulation, nasal articulation, fricative articulation, trill, lateral, etc.

Desempenho perceptual-auditivo e ortográfico de consoantes fricativas na aquisição da escrita

To investigate the perceptual-auditory and orthographic performances of students regarding identification of contrasts among the fricatives of Brazilian Portuguese, and to investigate the extent to which these two types of performances are related. Data from perceptual-auditory and orthographic performances of 20 children attending the two first grades of elementary education at a public school in Mallet (PR), Brazil, were analyzed. Data collection regarding auditory perception was based on the Assessment Tool in Speech Perception (PERCEFAL), using the software Perceval. Data collection regarding orthography was carried out through dictation of the same words used in the assessment tool PERCEFAL. We observed: more accuracy in perceptual-auditory than in orthographic skills; tendency of shorter response time and lesser variability in the perceptual-auditory hits than in the errors; mismatch of errors in orthographic and auditory perception, since, in perception, the highest percentage of errors involved the point of articulation of fricatives, while in orthography the highest percentage involved voicing. Although related to each other, perceptual-auditory and orthographic performances do not match term by term. Therefore, in clinical practice, attention should focus not only on the aspects that bring these two performances together, but also on the aspects that differentiate them.

Acoustic properties of Turkish voiceless fricatives

The investigation of acoustic parameters which differentiate place of articulation for fricatives has been limited to few languages. This study investigates the acoustic properties of Turkish voiceless fricatives representing three different places of articulation, /f, s, ∫/. For each fricative, spectral properties, duration, overall amplitude, F2 transition, and center of gravity were measured. Each fricative occurred in different vowel environments, in one and two word syllables and in different positions within a word. The participants were 6 (3 male, 3 female) native Turkish speakers. A total of 4320 tokens were analyzed. The findings showed that frequency range, spectral peak location, F2 transition and center of gravity are cues to place of articulation in Turkish. The findings showed that the frequency range is 1500-10500 Hz for /f/, 3500-10800 Hz for /s/, 1800-9400 Hz for /∫/. The spectral peak location measurements were; /s/ > /f/ > /∫/. The mean duration of fricatives were /∫/ >/s/ >/f/. The amplitude for fricatives are as follows; / ∫/ >/s/> /f/. The onset of F2 transition were; /∫/ >/s/> /f/ and the center of gravity measurements were; /s/ > /∫/ > /f/.

Effect of Linear Frequency Transposition on Speech Recognition and Production of School-Age Children

To investigate the clinical efficacy of linear frequency transposition (LFT) for a group of school-age children. A nonrandomized, within-subject design was implemented to investigate vowel and consonant recognition and fricative articulation of school-age children utilizing this feature. Ten children, aged 6 years and 3 months, to 13 years and 6 months from a special education school district participated in this study. Individual hearing thresholds ranged from normal to moderate in the low frequencies and from severe to profound in the high frequencies. Average language age of children was within 2.2 years of chronological age. Phoneme recognition and fricative articulation performance were compared for three conditions: (1) with the children's own hearing aids, (2) with an advanced hearing instrument utilizing LFT, and (3) with the same instrument without LFT. Nonsense syllable materials were administered at 30 and 50 dB HL input levels. Fricative articulation was measured by analyzing speech samples of conversational speech and oral reading passages. Repeated measures general linear model was utilized to determine the significance of any noted effects. Results indicated significant improvements in vowel and consonant recognition with LFT for the 30 dB HL input level. Significant improvement in the accuracy of production of high-frequency (HF) fricatives after six weeks of use of LFT was also observed. These results suggest that LFT is a potentially useful hearing aid feature for school-age children with a precipitous HF sensorineural hearing loss.

An MRI Study of the Effect of Vowel Context on English Fricatives

To gain a better understanding of the long-observed effects of vocalic context, the articulation of fricatives was investigated using Magnetic Resonance Imaging. Five speakers of American English were imaged while producing eight fricatives in the contexts [i-a-u-schwa]. Sagittal, axial and oblique-coronal volumes were acquired for each vowel-fricative combination. Acoustic recordings were made during scans and separately in an anechoic chamber. Vocal tract models were generated by aligning and superimposing all three stack orientations. The models reveal that a variety of articulatory strategies are employed in the production of English fricatives, and that vocalic context is significant. For some subjects, tongue shape differs little with vowel context; other subjects show highly varied tongue shape differences but little difference in lip rounding. Two subjects show significant variation with vowel context for every fricative, including [θ]; two show very little difference, even for [f]. The sublingual cavity in [sh] is extensive for two subjects, but only slightly bigger than in [s] for two other subjects. Tongue grooving in and behind the constriction also varies, and is especially evident in the oblique scans. Overall, more variation and effect of vowel context was observed than expected from the literature. [Funded by NIH-NIDCD-RO1-DC006705]

Influence of a Standard Electropalatography Artificial Palate Upon Articulation

Objective: This study investigated the influence of a standard electropalatography (EPG) palate upon speech articulation in 3 normal speakers under standard EPG testing conditions. Patients and Methods: Three adult females aged 26, 31 and 34 years read the experimental phrase ‘say CV again’ 5 times under 3 experimental conditions: normal speech (without a palate in situ), 45 min after EPG palate insertion and 3 h after EPG palate insertion. Consonants and vowels commonly used in EPG research were studied and included /t/, /s/ and /∫/ in the /i/, /a/ and /u/ vowel environments. Perceptual and acoustic analysis of the data was completed. Results: The results revealed varied patterns of adaptation across the 3 participants. Perceptual analysis suggested that 2 of the participants adapted to the presence of the palate; however, 1 did not. The presence of the palate resulted in significant changes to consonant duration for all 3 participants. Spectrally, production of /t/ was unaffected by the presence of the palate, while articulation of fricatives varied across the participants. Conclusion: Paired with a previous study examining the effects of an EPG palate upon speech articulation [McLeod S, Searl J: Am J Speech Lang Pathol 2006;15:192–206], the present data suggest that researchers and clinicians alike should be aware of the potential perturbing effects of the palate.

Articulation of fricatives: Evidence from X-ray microbeam data

Articulatory changes in /s/ over time give rise to the onset and offset of turbulence noise, but the small tolerances involved make it difficult to separately consider the effects of movement, phonetic context, and subject variation. Aerodynamic estimates of the constriction area have been shown to demonstrate a marked asymmetry, with the /s/ onset more rapid than offset [C. Scully, Speech Commun. 11, 1992]. Previous articulatory studies led us to expect an invariant tongue tip position, with jaw raising dependent somewhat on the following vowel. In order to investigate the timing of the constriction formation in fricatives, X-ray microbeam data [Westbury et al., 1994] for citation forms of /sVd/ for 15 vowels were studied. In fact, the tongue marker patterns during [s] vary both by following vowel and subject; subjects seem to have different apical-laminal strategies. The jaw reaches maximum height during [s] for each subject studied; that height does not appreciably vary with vowel. This indicates that jaw height is important specifically for /s/ production. One possibility is that the constriction is formed by the tongue, and turbulence noise is then maximized by the lower teeth being brought into position. [Work supported by NIH NIDCD R01 DC 006705.]

Sex-Related Acoustic Changes in Voiceless English Fricatives

This investigation is a comprehensive acoustic study of 4 voiceless fricatives (/f theta s /) in English produced by adults and pre- and postpubescent children aged 6-14 years. Vowel duration, amplitude, and several different spectral measures (including spectral tilt and spectral moments) were examined. Of specific interest was the pattern of normal development of the acoustic properties of fricatives and the nature of sex-specific patterns of fricative articulation in prepubescent children. Little evidence of amplitude or duration differences was found between speakers that was related to sex of the speaker. However, significant sex-specific differences in fricative articulation were found in all groups of speakers-even in the youngest children (ages 6-7 years)-although there was an indication that some of the acoustic differences between females and males is reduced or absent in the youngest children. Results from discriminant analysis demonstrated that a discriminant function based on the adult male tokens was generally better at classifying fricatives produced by male speakers than female speakers, regardless of age. This showed that sex-related differences (presumably a function of sex-linked vocal tract variation) were present even in the youngest speaker group. However, the classification accuracy of the female model showed a steady improvement with the increased age of the female speakers and may provide support for the claim that sex-related developmental differences may just be emerging in the youngest age group.

Acoustic characteristics of English fricatives

This study constitutes a large-scale comparative analysis of acoustic cues for classification of place of articulation in fricatives. To date, no single metric has been found to classify fricative place of articulation with a high degree of accuracy. This study presents spectral, amplitudinal, and temporal measurements that involve both static properties (spectral peak location, spectral moments, noise duration, normalized amplitude, and F2 onset frequency) and dynamic properties (relative amplitude and locus equations). While all cues (except locus equations) consistently serve to distinguish sibilant from nonsibilant fricatives, the present results indicate that spectral peak location, spectral moments, and both normalized and relative amplitude serve to distinguish all four places of fricative articulation. These findings suggest that these static and dynamic acoustic properties can provide robust and unique information about all four places of articulation, despite variation in speaker, vowel context, and voicing.

Investigation of the articulatory patterns of young adults with Down syndrome using electropalatography

Tongue movements for speech in three adults with Down syndrome and one normal speaking control were investigatedusing electropalatography (EPG) and diadochokinetic rate (DDK)techniques. The subjects with Down syndrome all showedsubstantially larger areas of tongue-palate contact comparedwith the control subject for alveolar sounds /t, d, n, l/, anddifferences in fricative articulation. Undershoot (incompleteclosure) was a feature of velar articulations /k, g/ in the subjectswith Down syndrome. Longer closure duration, longer consonanttransition times within clusters and consistently slower DDKrates were also noted. Asymmetry and variabilitywere evident in two of the subjects with Down Syndrome.The results support the hypothesis that people with Downsyndrome have difficulties with coordinating the rapid tonguemovements necessary for clear speech with impaired tonguemotility and motor programming as well as phonological delay.Implications for treatment are discussed.

On the Nature of Proto-Semitic *l

BASED ON THE REGULARITY of the correspondences supporting it, it would appear that reconstruction of Proto-Semitic *1 is uncontroversial and, by implication, uninteresting. It is the purpose of this note to demonstrate that, clear-cut though reconstruction of a Proto-Semitic *1 may be, it is not uninteresting. On the contrary, consideration of the phonetic nature of *l and of its reflexes has the potential to illuminate several problems of Semitic phonology, and, hence, is of great interest. In ordinary phonetic and phonological usage, the symbol /1/ denotes a voiced lateral approximant.' Two basic types of voiced lateral approximant are known, one with primary constriction in the alveodental region, and one in which this constriction is supplemented or supplanted by a velar constriction. Both types are found in many dialects of English, in complementary distribution: clear, alveolar [1]2 occurs in pre-vocalic position (e.g., leap), and dark, velarized [1] post-vocalically (e.g., pool) (Catford 1977, 19293). (In some dialects of American English, one variety or the other predominates: some New York urban dialects have velarized [1] in all positions, while some southern American dialects have only alveolar [1], [1] having changed to /w/ or been lost.) When the symbol 1 is used in transliterations, transcriptions, and reconstructions of forms in ancient languages, it is easy to interpret it as referring to a non-velarized, clear, approximant [1] rather than simply to a lateral with unspecified place and manner of articulation.3 In particular, given the apparent marked status of [1], it is easy to assume from consonantal inventories like that given in Moscati (1969) that Proto-Semitic *I was demonstrably a clear [1], despite the fact that this position has not to my knowledge been explicitly argued for. In fact, dispassionate consideration of the facts suggests, rather, that Proto-Semitic *1 was actually a velarized [1]. The primary evidence that Proto-Semitic *1 was actually dark *[I] comes from evidence regarding the nature of /1/ in Akkadian, Hebrew and Aramaic. In all three cases, phonological phenomena are best explained by the assumption that /1/ was [1]. The first case is the most straightforward. Steiner (1987) discusses a hitherto un-noted sound change in Hebrew and Aramaic: *aw becomes / ui/ rather than the regular /a/ when preceded by /1/. This change accounts for the difference between the parallel reduplicated forms 1lz^1v 'sprout' (< *lawlab < *lablab) and koxaiv 'star' (<*kawkab < *kabkab).4 Steiner suggests that this change would be explicable if the Hebrew/Aramaic /1/ were [1], at least in word-initial position. Rabin (1970) and Blau (1977) discuss an additional anomalous and sporadic development in Hebrew. In approximately 30 roots discussed by Rabin,5 *d appears as /d/ rather than the expected /z/. Rabin notes that in ' See Catford (1977, 132-33, 212) for discussion of the articulatory nature of approximant, fricative, and affricate laterals. Essentially, an approximant is produced with a more open articulatory channel than that involved in fricative articulation. As a result of this articulatory difference, both voiced and voiceless fricatives will be produced with sufficient airflow to produce acoustic turbulence, while only in the case of a voiceless approximant will turbulence be generated. To over-simplify only slightly, a voiced approximant will sound more vowel-like than will its voiceless equivalent. Besides /1/, other commonly recognized English approximants are /r w y/. 2 The various diacritic modifications of 1 used herein are to be interpreted as follows: [1] denotes a voiced alveolar lateral approximant and [1] the voiceless equivalent thereof. [I] denotes a voiceless alveolar lateral fricative. [1] denotes a voiced velarized alveolar lateral approximant and [1] its voiceless equivalent. For the distinction between approximants and fricatives, see the previous note. 3 The epistemological basis for this confusion appears to be the systematic ambiguity between 1 as the symbol for any member of the set of laterals, regardless of place and manner of articulation, as well as for the linguistically unmarked member of that set, i.e., a voiced alveolar lateral approximant. 4 Other forms resulting from this change are, according to Steiner (1987) liuah 'tablet', l0z 'almond tree', and 12 'if'. 5 Blau (1977, 110) rejects many of these candidates on semantic grounds. Secure cases include Hebrew ndr 'vow', 33

Analysis of formant transitions for English fricatives spoken by five male and five female talkers

Nonsense words of the form C′VC′VC′VC were recorded for the four voiceless fricatives of English [f,th,s,sh] in ten vowel environments by each of five male and five female talkers. The database was digitized at 16 000 samples/s and digital spectrograms were produced. Formant frequency values, F2 and F3, were measured by hand from the spectrograms at voicing onset and vowel midpoint for each CV transition. These data were examined in order to seek regularities of several possible forms: (1) invariant onset frequencies independent of speaker and vowel environment, (2) existence of locus frequencies that differ as a function of place of fricative articulation, but are similar across speakers, and (3) similar transition behavior (e.g., rising or falling F2 and/or F3) across speakers for a given vowel with no attempt to seek regularities across vowels. In all cases, distributions of transition-related measures across speakers for each place of articulation show disturbing amounts of overlap, even when male and female data are plotted separately. While it has often been said that [f] and [th] are distinguished perceptually by F2 and F3 transition behavior (because frication spectra are often quite similar), the data suggest that it will be difficult for a speech recognition device to make this distinction reliably from observed formant transition behavior in the general population. Some reassessment of the appropriate perceptual cues seems to be required. [Work supported in part by an NIH grant.]

Acoustic analyses of infant fricative and trill vocalizations.

Closants, or consonantlike sounds in infant vocalizations, were described acoustically using 16-kHz spectrograms and LPC or FFT analyses based on waveforms sampled at 20 or 40 kHz. The two major closant types studied were fricatives and trills. Compared to similar fricative sounds in adult speech, the fricative sounds of the 3-, 6-, 9-, and 12-month-old infants had primary spectral components at higher frequencies, i.e., to and above 14 kHz. Trill rate varied from 16-180 Hz with a mean of about 100, approximately four times the mean trill rate reported for adult talkers. Acoustic features are described for various places of articulation for fricatives and trills. The discussion of the data emphasizes dimensions of acoustic contrast that appear in infant vocalizations during the first year of life, and implications of the spectral data for auditory and motor self-stimulation by normal-hearing and hearing-impaired infants.