English Fricatives Research Articles

Articulation of English Consonants, Vowels and Diphthongs by Pashto Speakers in Khyber Pakhtunkhwa, Pakistan

This paper aims to examine the articulation of English consonants, vowels and diphthongs by Pashto Speakers in Khyber Pakhtunkhwa, Pakistan, and explores the problems they face in their English articulation due to the influence of mother tongue. A detailed experiment has been carried out to analyze the articulatory properties of /θ/ /ð/ /ɪ: /, /ɪ/ and /еɪ: / sounds spoken by Pashto speakers in Pakistan. The research reveals that Pashtun speakers of English language have a distinct pronunciation pattern of /θ/ and /ð/ sounds. This research provides a scientific justification to establish Pashto English as an independent deviant variety of RP Standard English Language. Based on the findings of the data collected from the recordings of 50 participants, it was concluded that thickness is low and frequencies of formants are considerably low as compared to RP sounds. In this regard, consonant phonemes of /θ/ and /ð/ sounds articulated by Pashto speakers are dissimilar to their Standard English (RP). They are produced as “Dental Plosives” instead of “Dental Fricatives”. The participants face great difficulty in pronouncing these English dental fricatives /ð/, /ɵ/ sounds, and they also face insurmountable problems in the regular plural forms. In relation to vowels and diphthongs in English language, major problems largely appeared in misunderstanding between /ɪ:/, /ɪ/ and /еɪ:/ sound production. The results of this study shall provide assistance to English language teachers and learners in teaching and learning English Language, especially in teaching and learning English pronunciation. It has been ascertained that special consideration should be given to these problematic consonants, vowels and diphthongs in order to avoid misunderstandings/confusion on the part of the listener.

English

This research examined how Thai undergraduates acquired English marked and unmarked fricatives in their interlanguage. It also determined what sounds the learners used to replace some fricatives and how variable they were. Based on the Markedness Differential Hypothesis (MDH), unmarked fricatives are /s/ and /f/, and marked ones are /ʃ/, /v/, /z/, /θ/, /ð/, and /ʒ/. The former are considered unmarked because they are available in Thai, whereas the latter are not. The participants included three groups: high, intermediate, and low proficiency students who were studied through three types of tasks: word list, sentence list, and oral interview. The word and sentence lists required the learners to produce the target fricatives in a formal situation, while the oral interview in a natural context. The results demonstrated that marked fricatives /v/, /z/, /θ/, /ð/, and /ʒ/ were difficult for the participants. Only the advanced informants could acquire unmarked /s/ and /f/ as well as marked /ʃ/ both initially and finally. According to the MDH, the learners produced /s/, /f/, and /ʃ/ before marked /v/, /z/, /θ/, /ð/, and /ʒ/. They also appeared to produce various substitutions for the problematic sounds. Plausible explanations to account for the Thai learners’ difficulty of English fricatives involve the first language (L1) transfer, distribution of a particular sound, voicing, systematic variability, and design of a task. In pronunciation classes, teachers or educators may design tasks appropriate for their learners and employ strategies that suit their learning style preferences. Keywords: English fricatives; interlanguage; L2 phonology; markedness; variability DOI: http://doi.org/10.17576/3L-2017-2301-02

Perceptual Identification and Perception of Sibilants of English Language by Turkish English Majors

Abstract Sibilants of English, /s, z, ʿ, ʿ, tʿ, dʿ/, are a combination of fricative and affricate consonants, produced with an audible hissing /s, z /and hushing / ʿ, ʿ, tʿ, dʿ/ overtones via perceptual intensity in pitches in their articulations. They are louder and their acoustic energy occurs at higher frequencies, which create some perceptual problems to Turkish students in English majors. The aim of this research is to explore whether Turkish English majors are able to perceive the articulatory distinction among English sibilant sounds. The 11 questions of the pre-test included one of the 6 English sibilants as the correct choice. In a soundproof language lab, the pronunciation coach articulated the correct choice three times. The correct answer was placed among the other four alternatives which were all fricatives and affricatives like [f, v, ɸ, β, θ, ð s, z, ʿ, ʿ, tʿ, dʿ, c, j, ɣ] in the same question. The English majors chose one of the alternatives as the correct answer. After the pre-test, the English fricatives and affricative were intensively studied three hours by means of exercises. Fifteen days later, the same pre-test was administrated to the participants as a post test. The students⿿ success rate is 73.83% for the pre-test and for the post-test is 91.60%, this showed that the participants improved their perception of the sibilant sounds of English

Quasi-neutralization in the acquisition of English coronal fricatives by native speakers of Japanese

Second language learners show various forms of mispronunciation, or modification, of target pronunciation, most perhaps due to direct native language transfer, but others, summarized here, to deflected contrast, hypercorrection and covert contrast. The present paper reports on a novel form of adaptation that we term ‘quasi-neutralization,’ in which acoustic characteristics of competing target phonemes are found within the same interlanguage segment (e.g., think [θɪŋk] pronounced as [θsiŋk]). The three English voiceless coronal fricatives /s/, /ʃ/, /θ/ were elicited from Japanese learners of English via two techniques: a wordlist reading task that encouraged participants to focus on their pronunciation, and a sentence construction task that diverted their attention from pronunciation. Among different types of modification, quasi-neutralization was observed predominantly when participants were conscious of their pronunciation, which could reflect their linguistic insecurity as learners. This research thus illuminates another of the strategies that learners employ in the acquisition of L2 pronunciation.

Place contrast enhancement: The case of the alveolar and retroflex sibilant production in two dialects of Mandarin

While segmental contrasts are under prosodically strong conditions, acoustic properties encoding the contrastive features are generally exaggerated, which gives rise to phonological enhancement. One exception that previous research found for such prosodic effects is on consonantal place of articulation (Cole, Kim, Choi, & Hasegawa-Johnson, 2007; Silbert & de Jong, 2008). Whether this is an issue of the nature of the segments under study, or a language-specific phenomenon is worth further investigation. This paper builds on Chuang and Fon's (2010) study of Taiwan Mandarin alveolar and retroflex sibilants and extends the examination to another dialect of Mandarin, Beijing Mandarin. With a series of map tasks to elicit natural yet well-controlled data, this study asks whether contrastive focus realizations of the alveolar–retroflex contrast vary across vowel contexts between the two dialects. Results show that, consistent with Silbert and de Jong's finding for place distinction in English fricatives, focal prominence may result in the exaggeration of non-contrastive dimensions (i.e., longer syllable and frication duration as well as higher frication amplitude) without enhancing feature-defining properties (i.e., a greater acoustic distance between alveolar and retroflex sibilants). It is suggested that the place feature, particularly in coronal sibilants, is generally less subject to cue-enhancing hyperarticulation, regardless of languages and dialects.

Steady as /∫i/ goes: The spectral kinematics of sibilant fricatives in English and Japanese

Sibilant fricatives are often treated as having steady-state articulatory targets, which fix their spectra throughout their duration; however, Iskarous et al. (2011) reported that the centroid frequency of English /s/ varies considerably across the fricative's time course. This study replicates their spectral analysis using a psychoacoustic measure (peak ERB) and then extends it to English /∫/ and Japanese /s, ɕ/. The time-varying spectral pattern of each fricative was approximated with a nine-point peak ERB trajectory, computed from 20-ms windows spaced evenly throughout each token. There were three notable results. First, adults did not produce the same spectral kinematic pattern for all sibilants in a given language: the spectral peak of English /s/ followed a concave trajectory, while /∫/ remained relatively flat. Second, phonetically similar fricatives from different languages did not necessarily show similar dynamical spectral patterns: the peak trajectory of /s/ was curved in both languages, but re...

Multidimensional scaling and order asymmetry of the acoustic change complex to voiceless fricatives in Polish, English, and Finnish listeners

The acoustic change complex (ACC) is a P1-N1-P2 onset response to changes between sounds measured using EEG, which when measured at a central location, is not thought to be affected by the language experience of the listener. Recent research has shown that with a pair of stimuli, there is an asymmetry between the ACC recorded when they are presented in one order compared to the other. This study used eight voiceless fricatives to measure the ACC to all possible pairs from EEG recordings of 15 English, Finnish, and Polish listeners. The ACC magnitude was used to perform multidimensional scaling to create a two dimensional perceptual space for each language that is driven by the spectral characteristics of the stimuli. Asymmetry occurred in all three languages depending on how peaky the first and second stimuli were. This asymmetry effect was greater for the Polish group, indicating that the Polish listeners' language experience increases their sensitivity to the spectral peakiness of fricatives. These results show that the ACC is in fact susceptible to native language effects, enhancing its application as a test for auditory speech processing.

Lung volume initiation levels and selected acoustic measures of English consonants

Watson, Ciccia, and Weismer (2003) described the relationship of initiating speech at different lung volumes to selected acoustic variables related to vowel production. It was found that some variables, such as dB SPL were related to a ‘direct' mechanical interaction with the breathing system. They also found that a variable, such as vowel-space, was reduced at low-lung volume initiation levels suggesting an indirect link between one subsystem, breathing, and another articulation. Using a similar procedure to Watson et al. (2003), we studied selected acoustic variables of English fricatives and stops. Participants read aloud a carrier phrase with a 2 syllable V—‘CV embedded within it. Participants were trained to initiate speech at 3 different lung volume levels: normal, low, and high. Data will be discussed in relation to those acoustic variables that have a more direct interaction with the breathing system, e.g., db SPL, and those with a less direct relationship with breathing, e.g., relative duration of voice-onset-time between cognate pairs of voiced and voiceless stop consonants, and the difference of first moment measures between sibilants.

L1 Transfer in the Production of Fricatives and Stops by Pattani-Malay Learners of English in Thailand

This study investigated the English fricative and stop pronunciation errors produced by Pattani-Malay learners of English. The participants, speaking L1 Malay, were recruited from fifth and sixth graders at Thamwittaya Mulniti School, Yala province, Thailand. The major research instruments used to examine the errors were the word list reading task and the sentence reading task. The findings of this research demonstrate that Pattani-Malay learners of English seemed to have difficulty in producing errors in some specific English fricative sounds in particular positions. The medial voiced labiodental fricative /v/ and the medial voiced interdental fricative /ð/ were apparently the most problematic. The errors in pronouncing the voiced labiodental fricative /v/ and the voiced interdental fricative /ð/ in the initial and final positions were ranked second, followed by the final voiced palato-alveolar fricative /?/ errors and the final voiceless interdental fricative /?/ errors respectively. The results revealed that the learner’s problems in pronouncing English fricatives and stops are mainly attributed to first language transfer.

The perception of English and Thai fricatives and affricates by Thai learners

English has eight voiceless-voiced fricatives /f, v, θ, Ð, s, z, ∫, and ȝ/ and two affricates /t∫ and dȝ/ in all positions. Thai, however, carries only two initial voiceless fricatives /f, s/ and one initial voiceless affricate /t∫/. In the literature, the acoustic cues for fricatives include the frication noise, the amplitude, and the fundamental and formant frequencies on the adjacent vowels. This research explores how Thai listeners can perceive the English fricatives and affricates, as opposed to the Thai set. Thirty-one English and fifteen Thai words with fricatives and affricates were chosen. Two native-American male speakers read all English words, and a native-Thai female speaker read all Thai words. All the words were acoustically measured for the acoustic cues and digitally modified for all 312 tokens with different quality and quantity. Twenty native-Thai listeners (14 females and 6 males) listened and identified each token whether it contained which original fricative or affricate. The results revealed that the correct responses of the Thai learners were at a higher rate (90–100%) for the Thai original and modified tokens, and at a lower rate (30–100%) for the English set. It is hoped that this study will shed light on to future perceptual studies.

Listener Expectations and Gender Bias in Nonsibilant Fricative Perception

The nonsibilant English fricatives /f/ and /θ / are known to be acoustically nonrobust. Using /f/ and /θ/ stimuli produced in CV, VCV, and VC syllables in /i α u/ contexts spoken by 10 talkers (5 male), we first replicate previous research suggesting that the most robust cues to this contrast are in the formant transitions in adjacent vowels. We also demonstrate vowel and syllable contextual differences that point to the contrast being most robust in /u/ contexts. In a series of perception experiments we go on to demonstrate effects of bias on perception of /f/ and /θ/ that derive from the uninformative nature of the frication noise, making them vulnerable to misperception in general, and especially in low-saliency contexts where the formant transition information is less robust. In experiment 1, listeners' classification of /f/ and /θ/ demonstrated a general bias to respond /f/ for fricatives produced by females and /θ/ for those produced by males. We hypothesize that the perceived concentrations of spectral energy in the fricative are shifted based on the concentration of energy in the vowel, which depend on a talker's gender. In experiment 2, vowel and frication noise portions were cross-spliced to probe this effect, resulting in the same gender-based bias. In a final experiment the vocalic information was removed and only the frication noise was presented to listeners for classification. In this task there was a general bias for /f/, regardless of the talker gender. Overall we demonstrate topdown gender effects in perception that originate in the strong indexical properties of adjacent vowels rather than being present in the frication noise itself.

The English palatoalveolar fricative in Korean speakers’ second language production

The English palatoalveolar fricative in Korean speakers’ second language production

A comparative cross-linguistic study of vocal tract shaping in sibilant fricatives in English, Serbian and Mandarin using real-time magnetic resonance imaging

An articulatory study of sibilant fricatives is described, with the goal of describing variability in lingual articulation across languages. Real-time magnetic resonance imaging (rtMRI) data were collected from three speakers each of English and Mandarin and two speakers of Serbian and reconstructed at a rate of 22.4 frames per second. Parallel acoustic data were also collected and subsequently denoised. Subjects spoke the segments /s/ and /S/ in symmetrical vowel contexts (e.g., “pa sap” for English and “asa” for Mandarin). Articulation was analyzed using a semi-polar grid overlaid on the image plane and midsagittal distance functions were obtained by measuring cross distances at ~0.5 cm intervals from the glottis to the lips. Analysis shows that place of articulation for /s/ is more anterior compared to /S/ across languages. Apical articulation is observed for /s/ across languages, while /S/ is produced laminally in English and apically in Serbian and Mandarin. Patterns of tongue shaping variability differ, as well, across languages. For instance, higher standard deviation is observed anterior to the place of articulation for /S/ in Mandarin, compared to Serbian and English. [Work supported by NIH.]

Multidimensional scaling of English fricatives using the acoustic change complex of electroencephalogram recordings

In electroencephalogram (EEG) recordings, there is a characteristic P1-N1-P2 complex after the onset of a sound, and a related complex, called the Acoustic Change Complex (ACC), when there is a change within a sound (e.g., a formant transition between two vowels). In the present study, the ACC was measured for all possible pairs of eight sustained voiced and voiceless English fricatives, in EEG recordings from native speakers of British English. The magnitude of the ACC was used as a similarity measure for multidimensional scaling (MDS), producing a two-dimensional perceptual space that related to both voicing and place of articulation. The results thus demonstrate that this combination of ACC and MDS can be effective for mapping multidimensional phonetic spaces at relatively early levels of auditory processing, which may be useful for evaluating the effects of language experience in adults and infants.

A psychoacoustic method for studying the necessary and sufficient perceptual cues of American English fricative consonants in noise.

In a previous study on plosives, the 3-Dimensional Deep Search (3DDS) method for the exploration of the necessary and sufficient cues for speech perception was introduced (Li et al., (2010). J. Acoust. Soc. Am. 127(4), 2599-2610). Here, this method is used to isolate the spectral cue regions for perception of the American English fricatives /∫, 3, s, z, f, v, θ, δ in time, frequency, and intensity. The fricatives are analyzed in the context of consonant-vowel utterances, using the vowel /α/. The necessary cues were found to be contained in the frication noise for /∫, 3, s, z, f, v/. 3DDS analysis isolated the cue regions of /s, z/ between 3.6 and 8 [kHz] and /∫, 3/ between 1.4 and 4.2 [kHz]. Some utterances were found to contain acoustic components that were unnecessary for correct perception, but caused listeners to hear non-target consonants when the primary cue region was removed; such acoustic components are labeled "conflicting cue regions." The amplitude modulation of the high-frequency frication region by the fundamental F0 was found to be a sufficient cue for voicing. Overall, the 3DDS method allows one to analyze the effects of natural speech components without initial assumptions about where perceptual cues lie in time-frequency space or which elements of production they correspond to.

Acoustic and perceptual similarities between Effutu and English fricatives: Implications for English as a second language

Volin & Skarnitzl (2010) describe a foreign accent as a set of pronunciation patterns, at both segmental and suprasegmental levels, which differ from pronunciation patterns found in the speech of native speakers (p.1010). Not only can these pronunciation patterns differ, they can also be similar in many ways. These similarities can be perceptual, acoustic and auditory, especially at the segmental level. This study investigates the acoustic and perceptual similarities between the fricatives /s/, /f/ and /∫/ of Effutu, a dialect of Awutu, and their English counterparts in the context of /a/ and /i/. Duration and spectral peak frequency are measured in order to achieve this. A discrimination task, Same-Different task, was administered to investigate listeners’ perceived similarity (or difference) judgments between the pairs of fricatives. Preliminary findings show that there are perceptual and acoustic differences in the durations of these segments cross-linguistically. This study contributes to cross-linguistic investigation of fricatives, and to second language acquisition. The findings also show that the use of acoustic and perceptual cues helps to establish differences between speech sounds in different languages, and that, ESL teachers can use these to develop appropriate ways of teaching English sounds to learners.

Understanding speech acoustics in an era of extreme cue-integration: Multi-dimensional phonetics reveals individual differences in fricative production

Phonological features are indicated by many acoustic cues (Lisker, 1986). Listeners must thus combine multiple cues to recognize speech (Nearey, 1990). A recent survey of cues to English fricatives identified 24 distinct, useful cues (McMurray & Jongman, 2011). This multi-dimensional nature of speech raises methodological challenges: cues do not contribute equally, and multiple cues contribute to the same phonetic features (e.g. voicing). We offer a solution, using McMurray and Jongman’s (2011) fricative database as a test. We used a logistic regression to predict the fricatives using measurements of 24 cues. We then sum the product of each cue value and its weight from the regression to determine the strength of the evidence for a given feature/phoneme (e.g. degree of “f-ness” vs. “v-ness”) for each token. By computing this for different subsets of cues, we can measure how classes of cues work in tandem. We illustrate this by examining the relative contribution of cues within the frication and those within the vocoid, as well as spectral and temporal cues, to show individual differences in fricative productions. These analyses offer a straightforward approach to conceptualizing speech perception in high multi-dimensional space, while also giving insights on the production of English fricatives.

Improved imaging of lingual articulation using real‐time multislice MRI

To develop a real-time imaging technique that allows for simultaneous visualization of vocal tract shaping in multiple scan planes, and provides dynamic visualization of complex articulatory features. Simultaneous imaging of multiple slices was implemented using a custom real-time imaging platform. Midsagittal, coronal, and axial scan planes of the human upper airway were prescribed and imaged in real-time using a fast spiral gradient-echo pulse sequence. Two native speakers of English produced voiceless and voiced fricatives /f/-/v/, /θ/-/ð/, /s/-/z/, /∫/- in symmetrical maximally contrastive vocalic contexts /a_a/, /i_i/, and /u_u/. Vocal tract videos were synchronized with noise-cancelled audio recordings, facilitating the selection of frames associated with production of English fricatives. Coronal slices intersecting the postalveolar region of the vocal tract revealed tongue grooving to be most pronounced during fricative production in back vowel contexts, and more pronounced for sibilants /s/-/z/ than for /∫/-. The axial slice best revealed differences in dorsal and pharyngeal articulation; voiced fricatives were observed to be produced with a larger cross-sectional area in the pharyngeal airway. Partial saturation of spins provided accurate location of imaging planes with respect to each other. Real-time MRI of multiple intersecting slices can provide valuable spatial and temporal information about vocal tract shaping, including details not observable from a single slice.

Deriving invariance by integrating cues computed relative to expectations

Invariance and variability are notions that have stimulated much research on the acoustics and perception of speech. While some invariance must exist to explain how listeners generally derive the same message from spoken input, the question remains at which level invariance occurs. The theory of acoustic invariance explicitly states that the invariance is found in the acoustic signal. While some phonemic distinctions do seem to be represented by invariant acoustic properties, it is clear that many acoustic cues are context-dependent. Normalization or compensation processes for coping with specific sources of variability have been proposed as solutions to this context-dependency. We examined acoustic properties for a large corpus of American English fricatives. We argue that the lack of invariance is not a major obstacle and demonstrate that it can be overcome by the use of multiple acoustic cues and a relatively simple compensation scheme by which cues are recoded relative to expectations derived from context (vowel quality and speaker). A comparison of this approach (C-CuRE, Computing Cues Relative to Expectations) [McMurray and Jongman, Psych. Rev. 118, 219–246 (2011)] to acoustic invariance and exemplar approaches suggests that only C-CuRE achieved a similar accuracy to listeners and showed the same effects of context.

Intra- and inter-speaker variability in duration and spectral properties of English /s/

This study investigates the speaker-specificity of acoustic characteristics of the English fricative /s/ and contributes background population statistics for use in forensic speaker comparison work. The intra- and inter-speaker variability in duration and spectral properties of /s/ was investigated in data from 30 young adult male speakers of Cambridge and Leeds English. Read speech was used in the present study to allow direct comparison across speakers. Segment duration was normalized for speaking rate. Spectra were filtered at 4 kHz in order to explore speaker discrimination performance at settings mimicking the bandpass filter effect of telephone transmission. Additional filters were applied at 8, 16, and 22.05 kHz to investigate discrimination with data from various frequency ranges. Spectral measures were calculated from a 40-ms window centered on the midpoint of each token. Although mean values display relatively little inter-speaker variation, the individuals at the extreme high and low ends of the distributions may be the best discriminated, particularly those at the extremes on more than one parameter. Discriminant analyses were conducted to determine the most speaker-specific predictors; relative performance was compared across the four filter conditions. The discriminatory ability of these parameters will also be presented using a likelihood ratio framework.