Alveolar Fricatives Research Articles

Native Speaker Perceptions of Accented Speech: The English Pronunciation of Macedonian EFL Learners

The paper reports on the results of a study that aimed to describe the vocalic and consonantal features of the English pronunciation of Macedonian EFL learners as perceived by native speakers of English and to find out whether native speakers who speak different standard variants of English perceive the same segments as non-native. A specially designed computer web application was employed to gather two types of data: a) quantitative (frequency of segment variables and global foreign accent ratings on a 5-point scale), and b) qualitative (open-ended questions). The result analysis points out to three most frequent markers of foreign accent in the English speech of Macedonian EFL learners: final obstruent devoicing, vowel shortening and substitution of English dental fricatives with Macedonian dental plosives. It also reflects additional phonetic aspects poorly explained in the available reference literature such as allophonic distributional differences between the two languages and intonational mismatch.

Chinese Children and Adolescents Acoustic Analysisof the Alveolar Fricatives in Multi-culture and Mono-culture Family Groups

Chinese Children and Adolescents Acoustic Analysisof the Alveolar Fricatives in Multi-culture and Mono-culture Family Groups

Perceptual and production training of allophones and phonemes in Spanish.

American English learners of Spanish often do not acquire native‐like pronunciation of intervocalic /d/, tap, and trill in words like CODO “elbow,” CORO “choir,” and CORRO “I run.” The trill proves difficult because it does not exist in English. Although the tap exists as an allophone of /t/ and /d/ in English, students of Spanish must learn to process it as a phoneme rather than an allophone. Similarly, learners have difficulty acquiring the spirantization of voiced stops, where intervocalic /d/ is produced as a voiced dental fricative or approximant. This study investigates whether American English learners of Spanish can be trained to perceive and produce the intervocalic /d/, tap, and trill contrasts in Spanish. Both perceptual and production training methods were used. Past research has reported that perceptual training alone improves both perception and production, and that production training alone improves both as well; however, the production training studies have not been limited to production as trainees have been able to listen to the training stimuli. This study systematically controls both training modalities and introduces a third training methodology that includes both perception and production to discover whether perceptual, production, or combination training is most effective. [Research supported by NSF.]

A Study of Voiced Alveolar and Palato-alveolar Fricative Production by Korean Learners of English

This study explores the production of voiced alveolar and palato-alveolar fricatives by Korean learners of English. A production experiment of minimal pairs with /z, з/ was conducted with Korean learners of English and native English speakers. The results indicated Korean learners' use of acoustic cues were different from that of native English speakers in their discrimination of minimal pairs. In one pair, Korean learners of English did not make distinctions at all. Segmental error patterns of Korean learners of English attested a preference of one pattern over the other: vowel insertion or affrication.

Cross‐language differences in the uptake of place of articulation.

There are cross‐language differences in the use of coarticulatory cues for fricative identification. Listeners with spectrally similar fricatives in their native phoneme inventories rely more on the information in the surrounding vowels than listeners with spectrally distinct fricatives. The present study examined whether such cross‐language differences result in differences in the temporal uptake of information specifying fricatives. In a gating study native listeners of Dutch and Italian, both languages with spectrally distinct fricatives were compared with Spanish and Polish listeners. The Spanish fricative inventory contains the spectrally similar labiodental and dental fricatives. The Polish fricative repertoire contains postdental, alveolar, and alveolopalatal fricatives. The questions addressed were whether the presence of spectrally similar fricatives leads to: (1) reliance on cues, which are secondary for listeners with distinct fricatives; (2) an uptake of information specifying place of articulation in particular for fricatives; (3) an uptake of information from coarticulatory cues preceding or following the consonant. Listeners identified fricative and stop targets in gated CV and VC syllables. The results show that listeners optimize their uptake of information to the demands of their native phoneme inventories and rely on more sources of information only for distinctions between several similar places of articulation.

Stop‐like modification of dental fricatives in Indian English: A preliminary study to perceptual experiments.

Stop‐like modification of dental fricatives occurs in both American English and foreign accents of English (Zhao, Ph.D. thesis, 2007). This study examines stop‐like word‐initial /Ð/ in Indian English to determine its frequency and compare it with American English. Acoustic analysis on unscripted telephone recordings of 40 Indian English speakers showed that of 161 total word‐initial /Ð/ instances, 61% were stop‐like. The modification occurred most frequently in utterance‐initial contexts, after stops, and after fricatives, and least after vowels and liquids. The variable occurrence of the modification across many contexts suggests that it may result from physiological conditions rather than from a phonological rule. If the modification is physiologically conditioned, differences in modification frequency between dialects may indicate dialectal differences in articulation. For example, comparison with American English showed that stop‐like /Ð/ was more common in Indian English across all contexts, particularly after fricatives, consistent with the tendency of Indian English to substitute bilabial stops for labiodental fricatives (e.g., /f/ and /v/), which provides a context more conducive to stop‐like /Ð/. Further investigation of varying cross‐dialectal frequencies of stop‐like modification could uncover additional dialectal differences in articulation and determine how such articulatory differences might affect cross‐dialect perception.

An electropalatographic investigation of linguopalatal contact in participants with acquired apraxia of speech: A quantitative and qualitative analysis

The current study aimed to provide a comprehensive analysis of linguopalatal contact patterns in participants with acquired apraxia of speech (AOS). Tongue‐to‐palate contacts were recorded for three participants with AOS during consonant singletons and consonant clusters using the Reading Electropalatograph (EPG3) system. Amount and pattern of linguopalatal contact were analysed using qualitative and quantitative analysis methods and the degree of spatial variability was quantified. The results obtained for each of the apraxic speakers were individually compared to those obtained by a control group (n = 5). Misdirected articulatory gestures and distorted spatial configurations for alveolar fricatives were detected in the linguopalatal contact patterns recorded for each of the participants with AOS. Lingual overshoot, right‐side dominant contact, and increased spatial variability were also evidenced by some participants. True omission errors were absent. Overall, the combination of qualitative and quantitative analysis techniques proved valuable in providing a comprehensive analysis of linguopalatal contact in AOS. Results provided support for a motoric account of articulatory and prosodic deficits in AOS.

An articulatory view of Kinyarwanda coronal harmony

Coronal harmony in Kinyarwanda causes alveolar fricatives to become postalveolar preceding a postalveolar fricative within a stem. Alveolar and postalveolar stops, affricates and palatals block coronal harmony, but the flap and non-coronal consonants are reported to be transparent. Kinematic data on consonant production in Kinyarwanda were collected using electromagnetic articulography. The mean angle for the line defined by receivers placed on the tongue tip and blade was calculated over the consonant intervals. Mean angle reliably distinguished alveolar and postalveolar fricatives, with alveolars showing a lower tip relative to blade. Mean angle during transparent non-coronal consonants showed a higher tip relative to blade than in contexts without harmony, and the mean angle during transparent [m] was not significantly different than during postalveolar fricatives. This is consistent with a model where Kinyarwanda coronal harmony extends a continuous tip-blade gesture, causing it to be present during 'transparent' segments, but without perceptible effect.

Identification of the English Alveolar Fricative by Koreans

Identification of the English Alveolar Fricative by Koreans

Contrast and covert contrast: The phonetic development of voiceless sibilant fricatives in English and Japanese toddlers

This paper examines the acoustic characteristics of voiceless sibilant fricatives in English- and Japanese-speaking adults and the acquisition of contrasts involving these sounds in 2- and 3-year-old children. Both English and Japanese have a two-way contrast between an alveolar fricative (/s/), and a post-alveolar fricative (/ʃ/ in English and /ɕ/ in Japanese). Acoustic analysis of the adult productions revealed cross-linguistic differences in what acoustic parameters were used to differentiate the two fricatives in the two languages and in how well the two fricatives were differentiated by the acoustic parameters that were investigated. For the children's data, the transcription results showed that English-speaking children generally produced the alveolar fricative more accurately than the post-alveolar one, whereas the opposite was true for Japanese-speaking children. In addition, acoustic analysis revealed the presence of covert contrast in the productions of some English-speaking and some Japanese-speaking children. The different development patterns are discussed in terms of the differences in the fine phonetic detail of the contrast in the two languages.

Substitution of dental fricatives in English by Dutch L2 speakers

This paper investigates the nature of the substitutions used for the dental fricatives (/θ/ and /ð/) by Dutch learners of English as a second language. By means of an OT analysis, the underlying reasons for the difficulties encountered with these sounds are brought to light. The present data reveal that phonetics (or acoustics) rather than phonology plays a major role in the selection of the phonemes used to substitute the dental fricatives.

Phonological Changes of the Shaowu Dialect in the past 100 years, with Special Reference to Shauu K’iong Loma T’se

This paper aims to examine the phonological changes in the Shaowu dialect as spoken in northwestern Fujian during the past 100 years. The study is based upon a close comparison of two recordings, produced by Rev. Joseph E. Walker (Shauu K'iong Loma T'se, 1887) and Chen Zhangtai et al. (Minyu Yanjiu, 1991), respectively. A wordlist in full romanization, Shauu K'iong Loma T'se (hereafter LMT) contains 1,589 readings of both colloquial and literary forms in the Shaowu dialect. The phonological system as shown in LMT displays several phonological peculiarities that have disappeared in the modern recording. For instances, (1) medial - u- appears after alveolar and bilabial stops; and (2) vowel -μ appears after alveolar affricatives and fricatives. All these discrepancies are interpreted as phonological changes; and nine rules are designed to account for the development. It is found that some of these changes were induced by the prestigious neighboring Gan dialects. As a result, the Shaowu dialect and the Gan dialects became increasingly alike in the past century.

The articulation of consonants in Kinyarwanda’s sibilant harmony

Kinyarwanda’s sibilant harmony causes alveolar /s, z/ to become retroflex when preceding a retroflex fricative within a stem. Intervening coronal stops block sibilant harmony, but bilabial and velar consonants are transparent. This study investigates the production of Kinyarwanda’s sibilant fricatives and also examines transparent and opaque consonants in the system. Articulatory kinematic data were collected for a native speaker of Kinyarwanda using electromagnetic articulography. This allowed calculation of the mean angle for receivers affixed to the tongue tip and blade over the target consonant intervals. Average mean angle reliably and robustly distinguished alveolar and retroflex fricatives, with alveolars showing a lower tip relative to blade. No significant difference in mean angle was found for /t/ in contexts where it blocked retroflex sibilant harmony versus ones where it preceded an alveolar fricative, confirming that /t/ does not participate in the harmony. However, in contexts where /m/ and /k/ are perceived as transparent to sibilant harmony, their mean tip-blade angle was significantly different from contexts where harmony did not occur. Furthermore, mean angle during transparent /m/ showed no significant difference from mean angle during retroflex fricatives, suggesting that tongue tip-blade angle conducts strongly and systematically through transparent consonants but without perceptible effect. [Work supported by NIH, USC URP.]

Acoustic analysis of European Portuguese uvular [χ, [Voiced uvular fricative]] and voiceless tapped alveolar [Voiceless dental or alveolar tap] fricatives

In a study of European Portuguese fricatives it was noted that /R, / were often realized as [χ, ], which are, respectively, unvoiced and voiced uvular fricative, and voiceless tapped alveolar fricative. Although these phones have not previously been recognized as occurring in European Portuguese, they occurred in 115 words out of a corpus of 1304 words, out of which 107 words could be analysed, in recordings made by four native speakers (two men, two women). Time- and frequency-averaged power spectral characteristics are presented, together with a detailed temporal analysis. The frequencies of high-amplitude peaks in the [χ] and [] spectra clearly indicate a back place of articulation, with median duration across subjects and words of 69 ms and 35 ms. The short (approximately 20 ms), noisy acoustic signal in [] suggests a stop-like manner of articulation, but the turbulence noise characteristics, similar to fricatives, differ from the transient burst noise of plosives.

Developmental processes in production of Korean /s/ and /s*/

The purpose of this study was to investigate development of Korean children’s productions of tense and lax Korean s. Korean alveolar fricatives are acquired late; /s*/ is generally later than /s/. However, little is known about developmental processes in acquiring the contrast between tense and lax Korean alveolar fricatives. Twenty typically developing monolingual Korean children between 4 and 8 and ten monolingual Korean adults were recruited in Korea. All children fell within normal limits on both a Korean articulation test and a standardized Korean vocabulary test. A picture-naming picture task elicited productions of initial fricatives, alveolar stops, and affricates followed by /a, i, u/ in monosyllabic words. Production error patterns will be analyzed to describe general developmental trends in production. More importantly, the contrast between productions of /s/ and /s*/ will be presented based on acoustic parameters including frication durations, centroid frequency, and harmonic-related amplitude measurements. Finally, similarities and differences in each acoustic parameter will be compared between adults and children. Results will discuss which acoustic parameter(s) effectively describe the distinction between productions of /s/ and /s*/ as well as differences between productions of adults and children between age 4 and 8.

Acoustic influence in crosslanguage phone mapping: Sibilant fricative place mismatch from English to Korean

The loanword adaptation and second language production of the English voiceless palatoalveolar fricative into Korean shows an interesting mismatch in tongue position. Korean palatalizes its alveolar fricative to alveolopalatal before high front vocoids. However, English voiceless palatoalveolar fricative before a high front vowel is adapted as an alveolar fricative with the secondary articulation of lip rounding, instead of an alveolopalatal. This paper argues that the failure to use the articulatorily closer Korean alveolopalatal fricative is due to Korean listeners’ interpreting English acoustic patterns in terms of the phonetic, especially acoustic, expectations of their native language. That is, Korean listeners attend more to the peak frequency of the English fricative than to the actual tongue position, and map it to their native fricative sound with the spectral peak at the closest frequency. Data collected from female speakers of American English and Korean show that, from fricative midpoint to end, the highest intensity spectral peaks are located at similar frequencies for English palatoalveolar and Korean rounded alveolar fricatives, while those of the Korean alveolopalatal are 1500–2000 Hz higher. This serves as another piece of evidence that second language/loanword adaptation is crucially affected by fine details of L1 and L2 phonetics.

Language-specific relevance of formant transitions for fricative

Although the consonant inventories of Dutch, German, English, and Spanish are similar in size, the fricative inventories differ: English and Spanish distinguish labio-dental versus dental fricatives, whereas Dutch and German do not. Three phoneme-monitoring experiments investigated whether the relevance of formant transitions varies across languages, and whether it depends on the types of fricatives in a language. Native Dutch, German, English, and Spanish listeners detected a target fricative, /s/ or /f/, in nonwords. Half of the nonwords were cross spliced to produce misleading formant transitions: an /s/ replaced an /f/, or vice versa. Dutch and German listeners were unaffected by the misleading formant transitions, whereas Spanish listeners missed significantly more fricatives surrounded by misleading formant transitions; these results were obtained whether stimuli were originally spoken by a Dutch or Spanish speaker. English listeners showed the same sensitivity to formant transitions as the Spanish. Despite previous reports that formant transition cues are of negligible significance for fricative identification (Klaassen-Don, 1983), the present findings show that formant transitions are indeed relevant for listeners whose native language distinguishes labio-dental versus dental fricatives. Listeners relied on the transitions even though no dental fricatives occurred in these stimuli, and independently of the speaker’s native language.

Enhancement of distinctiveness in strident fricatives: An example from Mandarin Chinese

Strident fricatives in Mandarin may be followed by fricative vowels, which are made with the tongue body in essentially the same position as in the corresponding fricative (Ladefoged and Maddieson, 1996). Specifically, the vowel [i] may occur only after the palatalized fricative, the apical vowel after the alveolar fricative, and the retroflex vowel after the palatoalveolar fricative. Given the complementary distribution, the three phonetically distinct vowels are generally considered allophones. Under the view that the implementation of discretely specified distinctive features may be enhanced by gradient, non-contrastive articulatory gestures to maintain perceptual distinctiveness (Keyser and Stevens, 2003), it is proposed that the three vowels are derived from an underlying [i] and are modified to enhance the defining articulatory and acoustic attributes of the fricatives. Acoustic data from six speakers indicate that the defining acoustic attributes for the fricatives, i.e., spectral prominences in discrete frequency ranges, are associated with distinct tongue configurations. The articulatory and acoustic properties of the palatalized fricative is most compatible with those of [i], whereas the tongue body backing gesture in the alveolar and palatoalveolar fricatives are consistent with lowered F2 frequency in the apical and retroflex vowels. [Work supported by NIH.]

Children's consonant inventories after extended cochlear implant use.

Qualitative descriptions of the consonant inventories of 12 children who have used cochlear implants for at least 5 years are provided, together with description of sound correspondences between children's systems and the ambient language (English). Productions of English words were elicited in a picture-naming task, and a consonant inventory for each child was determined. Results showed that the consonant inventories of children who use cochlear implants are not simply subsets of the inventory of the ambient language, but rather unique sets of segments that may include consonants not in the ambient inventory. Comparison of the inventories of oral communication users and total communication users revealed qualitative differences between the 2 groups, based on the presence or absence of both English and non-English sound segments. Inventories of oral communication users tended to contain more English segments (e.g., alveolar fricatives, velar stops, velar nasals) than did the inventories of total communication users. Conversely, specific non-English segments, such as uvular stops, tended to occur in the inventories of total communication users more than in inventories of oral communication users. Therefore, a complete understanding of the phonological systems of children who use cochlear implants depends on full accounts of their segment inventories. Such understanding may affect decisions regarding habilitation procedures, insofar as successful acquisition of a linguistic system involves not only the inclusion of all ambient sound segments, but also the exclusion of all nonambient ones.

Defining and measuring speech movement events.

A long-held view in speech research is that utterances are built up from a series of discrete units joined together. However, it is difficult to reconcile this view with the observation that speech movement waveforms are smooth and continuous. Developing methods for reliable identification of speech movement units is necessary for describing speech motor behavior and for addressing theoretically relevant questions about its organization. We describe a simple method of parsing movement signals into a series of individual movement "strokes," where a stroke is defined as the period between two successive local minima in the speed history of an articulator point, and use that method to segment speech-related movement of marker points placed on the tongue blade, tongue dorsum, lower lip, and jaw in a group of healthy young speakers. Articulator fleshpoints could be distinguished on the basis of kinematic features (i.e., peak and boundary speed, duration and distance) of the strokes they produce. Further, tongue blade and jaw fleshpoint strokes identified to temporally overlap with acoustic events identified as alveolar fricatives could be distinguished from speech strokes in general on the basis of a number of kinematic measures. Finally, the acoustic timing of alveolar fricatives did not appear to be related to the kinematic features of strokes presumed to be related to their production in any direct way. The advantages and disadvantages of this simple approach to defining movement units are discussed.