Fricative Sounds Research Articles

Phonetic training and non-native speech perception — New memory traces evolve in just three days as indexed by the mismatch negativity (MMN) and behavioural measures

Language-specific, automatically responding memory traces form the basis for speech sound perception and new neural representations can also evolve for non-native speech categories. The aim of this study was to find out how a three-day phonetic listen-and-repeat training affects speech perception, and whether it generates new memory traces. We used behavioural identification, goodness rating, discrimination, and reaction time tasks together with mismatch negativity (MMN) brain response registrations to determine the training effects on native Finnish speakers. We trained the subjects the voicing contrast in fricative sounds. Fricatives are not differentiated by voicing in Finnish, i.e., voiced fricatives do not belong to the Finnish phonological system. Therefore, they are extremely hard for Finns to learn. However, only after three days of training, the native Finnish subjects had learned to perceive the distinction. The results show striking changes in the MMN response; it was significantly larger on the second day after two training sessions. Also, the majority of the behavioural indicators showed improvement during training. Identification altered after four sessions of training and discrimination and reaction times improved throughout training. These results suggest remarkable language-learning effects both at the perceptual and pre-attentive neural level as a result of brief listen-and-repeat training in adult participants.

Use of an advanced 3-T MRI movie to investigate articulation

To develop a magnetic resonance imaging (MRI) movie to reveal the dynamic movement of articulators and teeth. Five healthy females with normal occlusion participated in this study. Various concentrations of MRI contrast media (ferric ammonium citrate [FAC]) were tested for visualization of teeth, according to facial markers and with the use of a gel. Custom-made circuitry was connected to synchronize pronunciation of fricative sounds (/asa/) with scans. Three gradient echo sequences (True fast imaging with steady state precession [true FISP], FISP, and fast low angle shot [FLASH]) with a segmented cine were tested with the use of repetition times (TRs) of 9 ms and 31.5 ms. The MRI movie images were superimposed over the boundaries of teeth. The images produced during pronunciation, using the two different TRs (9 ms and 31 ms), were compared to assess the position of the lips and the tongue. Images obtained using the FLASH sequence, with a TR of 9 ms or 31.5 ms, can be used for diagnostic purposes. A TR of 9 ms, with 161 continuous images acquired, produced the highest-quality images of teeth, with few artifacts present. Pronunciation of the consonant "s" was clearly discernable. Our 3-T MRI movie system, with a temporal resolution less than 9 ms, can provide detailed information pertaining to variations in speech or oropharyngeal function.

Categorical effects in fricative perception are reflected in cortical source information

Previous research in speech perception has shown that category information affects the discrimination of consonants to a greater extent than vowels. However, there has been little electrophysiological work on the perception of fricative sounds, which are informative for this contrast as they share properties with both consonants and vowels. In the current study we address the relative contribution of phonological and acoustic information to the perception of sibilant fricatives using event-related fields (ERFs) and dipole modeling with magnetoencephalography (MEG). We show that the field strength of neural responses peaking approximately 200ms after sound onset co-varies with acoustic factors, while the cortical localization of earlier M100 responses suggests a stronger influence of phonological categories. We propose that neural equivalents of categorical perception for fricative sounds are best seen using localization measures, and that spectral cues are spatially coded in human cortex.

A Class of Neuro-Computational Methods for Assamese Fricative Classification

Abstract In this work, a class of neuro-computational classifiers are used for classification of fricative phonemes of Assamese language. Initially, a Recurrent Neural Network (RNN) based classifier is used for classification. Later, another neuro fuzzy classifier is used for classification. We have used two different feature sets for the work, one using the specific acoustic-phonetic characteristics and another temporal attributes using linear prediction cepstral coefficients (LPCC) and a Self Organizing Map (SOM). Here, we present the experimental details and performance difference obtained by replacing the RNN based classifier with an adaptive neuro fuzzy inference system (ANFIS) based block for both the feature sets to recognize Assamese fricative sounds.

Moving targets and unsteady states: “Shifting” productions of sibilant fricatives by young children

The English voiceless sibilant /s/--/ʃ/ contrast is one that many children do not acquire until their adolescent years. This protracted acquisition may be due to the high level of articulatory control that is necessary to the successful production of an adult-like sibilant, which involves the coordination of lingual, mandibular, and pulmonic gestures. Poor coordination among these gestures can result in the acoustic properties of the noise source or the vocal tract filter changing throughout the timecourse of the frication, to the extent that the phonetic percept of the frication noise changes across its duration. The present study examined such “shifting” productions of sibilant fricatives by native English-acquiring two- through five-year-old children, which were identified from the Paidologos corpus as those productions where the interval of frication was transcribed phonetically as a sequence of fricative sounds. There were two types of shift in frication quality: (1) a gradual change in the resonant frequencies in the spectrogram, suggesting a repositioning of the oral constriction; and (2) an abrupt change in the level of the frication, suggesting a switch in the noise source. Work is underway to develop measures that differentiate these two types of shift, and that suggest their underlying articulatory causes.

Study of the effects of vocal tract constriction on glottal vibration.

Characteristics of glottal vibration are affected by the obstruction to the flow of air through the vocal tract system. The obstruction to the airflow is determined by the nature, location, and extent of constriction in the vocal tract during production of voiced sounds. The effects of constriction on glottal vibration are examined for six different categories of speech sounds having varying degree of constriction. The effects are examined in terms of source and system features derived from the speech and electroglottograph signals. It is observed that a high degree of constriction causing obstruction to the flow of air results in large changes in these features, relative to the adjacent steady vowel regions, as in the case of apical trill and alveolar fricative sounds. These changes are insignificant when the obstruction to the airflow is less, as in the case of velar fricative and lateral approximant sounds. There are no changes in the excitation features when there is a free flow of air along the auxiliary tract, despite constriction in the vocal tract, as in the case of nasals. These studies show that effects of constriction can indeed be observed in the features of glottal vibration as well as vocal tract resonances.

Neural Coding of Phonemic Fricative Contrast With and Without Hearing Aid

To determine whether auditory event-related potentials (ERPs) to a phonemic fricative contrast ("s" and "sh") show significant differences in listening conditions with or without a hearing aid and whether the aided condition significantly alters a listener's ERP responses to the fricative speech sounds. The raw EEG data were collected using a 64-channel system from 10 healthy adult subjects with normal hearing. The fricative stimuli were digitally edited versions of naturally produced syllables, /sa/ and /∫a/. The evoked responses were derived in unaided and aided conditions by using an alternating block design with a passive listening task. Peak latencies and amplitudes of the P1-N1-P2 components and the N1' and P2'' peaks of the acoustic change complex (ACC) were analyzed. The evoked N1 and N1' responses to the fricative sounds significantly differed in the unaided condition. The fricative contrast also elicited distinct N1-P2 responses in the aided condition. While the aided condition increased and delayed the N1 and ACC responses, significant differences in the P1-N1-P2 and ACC components were still observed, which would support fricative contrast perception at the cortical level. Despite significant alterations in the ERP responses by the aided condition, normal-hearing adult listeners showed distinct neural coding patterns for the voiceless fricative contrast, "s" and "sh," with or without a hearing aid.

청각장애 아동과 일반 아동의 마찰음에 나타난 음향음성학적 특성 비교

Alveolar fricative sounds /s/ and /s'/ are learned last for normal children in the speech development process for Koreans. These are especially difficult to articulate for hearing-impaired children often causing articulation errors. The acoustic phonetic evaluation uses testing tools to provide indirect and object information. These objective resources can be compared with standardized resources on speech when interpreting the results of a test. However, most previous studies in Korea did not consider acoustic studies that used the spectrum moment values of hearing-impaired children. Therefore, this study was conducted to compare the characteristics of hearing-impaired children's pronunciation of fricative sounds using spectrum moment values. For this purpose, the study selected a total of 10 hearing-impaired children (5 boys and 5 girls) currently in 3rd or 5th grade and attending one of the elementary schools in Seoul or Gyeonggi-do. For the selection process, their age, type of hearing aid, implantation of hearing aid (CI) before two years of age, hearing capacity (dB) before and after wearing the hearing aid, duration of speech rehabilitation, and time of learning alveolar fricative sounds were all considered. Also, 10 normal children (5 boys and 5 girls) were selected among 3rd or 5th grade students attending one of the elementary schools in Seoul or Gyeonggi-do. The subjects were asked to read the carrier sentence, "I say _______," including a list of 12 meaningless syllables composed of CV and VCV syllables, including alveolar fricative sounds /s/ and /s'/ and vowels /a/, /i/, and /u/. The recorded resources were processed through the Time-frequency Analysis Software Program to measure M1 (mean), M2 (variance), M3 (skewness), and M4 (kurtosis) of the fricative noise. No significant differences were found when comparing spectrum threshold values in the acoustic phonetic characteristics of hearing-impaired children and normal children in alveolar fricative sound pronunciation according to vowels /a/, /i/, and /u/, alveolar fricative sounds /s/ and /s'/, and syllable structure (CV, VCV) other than, for M3 in the comparison of groups according to disability. In the comparison of syllable structures, there were statistically significant differences in M1, M2, M3, and M4 with clinical significance. However, there was no significant difference in results when comparing the alveolar fricative sounds according to the vowels.

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.

HOW DO THE NON-TARGET PRONUNCIATIONS OF THE CONSONANTS /θ/ AND /ð/ BY BRAZILIAN LEARNERS OF ENGLISH AFFECT COMPREHENSIBILITY?

ABSTRACT: When learning English, Brazilian learners tend to replace the consonant sound /θ / with /s/, /t/, or /f/, and replace / ð/ with /z/, /d/, or /v/ (REIS, 2006). The objective of this study is to analyze if the non-target pronunciations of these consonant sounds by Brazilians hinder comprehensibility, as judged by English native speakers. Ten speech samples containing the pronunciation of the sounds /θ/ and / ð/ by Brazilians were collected and presented to a group of eleven native English speakers. The listeners were asked how difficult it was for them to understand the words that contained these consonant sounds. The results indicate that non-standard pronunciations of the interdental fricative sounds by Brazilians affect comprehensibility. KEYWORDS : comprehensibility; English interdental fricatives; Brazilian learners.

SUNDANESE STUDENTS’ PRODUCTION OF ENGLISH DENTAL FRICATIVE CONSONANT SOUNDS

This research attempts to investigate the production of English dental fricative sounds by Sundanese students of Universitas Gadjah Mada. It aims to investigate the level of acceptability and to find out the possible factors which influence their production of these sounds. 700 sentences containing the four dental fricative consonants were obtained and used as the data of the research. The students’ production of the four consonants was then assessed by a native speaker of English for their acceptability. The results of this research show that the acceptability level as judged by the informant of the students’ production of the dental fricative sounds is low, only 13.80% on average. The highest acceptability is in the sound [f] with 45.56%. The second highest acceptability is in the sound [v] which is scored 5%. It is followed by the sound [θ] which is scored 2.78%, and the sound [ð] with 1.88%. In general, the production of the dental fricative sounds produced by Sundanese students is judged as not clear by the native speaker.

Influência do contexto silábico da palavra no julgamento perceptivo-auditivo do ceceio produzido por pré-escolares

OBJETIVOS: investigar a ocorrência do ceceio em fricativas produzidas por crianças com alterações oclusais e analisar a influência do contexto silábico da fricativa no julgamento auditivo do ceceio. M ÉTODO: estudo prospectivo, em que as gravações de 428 palavras, produzidas por 15 crianças (idade média de 5 anos e 1 mês) foram julgadas auditivamente por três fonoaudiólogos com experiência no julgamento de alterações de fala. As palavras utilizadas foram constituídas pelas consoantes fricativas não vozeadas, alveolar e pós-alveolar, inseridas em posição tônica, precedida das vogais [i, a, u]. Obteve-se concordância intra-juiz (quase perfeita) e inter-juiz (total, 100%) previamente à análise dos aspectos de interesse. RESULTADOS: embora presente na fala de todas as crianças, identificou-se ceceio em 25,23% do total das palavras. Houve aumento significante do ceceio para: (a) fricativa alveolar em ataque inicial, (b) fricativa alveolar em ataque inicial em relação à coda medial (p=0,001) e (c) fricativa alveolar em relação à fricativa pós- alveolar (p<0,001). Não se observou diminuição do ceceio em relação às vogais co-articuladas. CONCLUSÃO: a ocorrência do ceceio é dependente do contexto silábico, (com maior ocorrência na fricativa alveolar, em posição de ataque inicial), devendo o mesmo ser considerado para fins clínicos e de pesquisa sobre o ceceio.

阻害壁の弾性率が流体音に与える影響∼In vitro 前歯部口腔モデルを用いた無声摩擦音と阻害壁振動の同時計測∼

阻害壁の弾性率が流体音に与える影響∼In vitro 前歯部口腔モデルを用いた無声摩擦音と阻害壁振動の同時計測∼

Relationship between Occlusion and Lisping in Children with Cleft Lip and Palate

The literature suggests that individuals with history of cleft lip and palate who present with midfacial growth deficiency are at higher risk of presenting lisping. The relationship between distortions during production of linguoalveolar fricative sounds and the severity of malocclusion, however, has not been established for the population with cleft. To study the association between lisping and dental arch relationship. Speech samples and dental arch casts were obtained from 106 children with operated unilateral cleft lip and palate (UCLP) during the stage of mixed dentition and before orthodontic treatment. Videotaped productions of the phrase /u saci saiw sedu/ were rated by speech-language pathologists for the identification of lisping during [s]. Dental arch casts were rated by orthodontists using the Goslon Yardstick and the Five-Year Index to establish dental arch relationship. Multiple logistic regression showed no significant association between lisping and dento-occlusal index (p = .802) and age (p = .662). Substantial interjudge agreement during auditory-perceptual ratings was found (kappa = .63). Almost perfect agreement was found between orthodontists while establishing the dental arch relationship (kappa = .81). This study failed to reveal an association between lisping and dental arch relationship in children with operated UCLP. Multiple variables may play a role in determining occurrence of lisping, warranting further investigation.

Occurrence of consonant production errors in liquid phonemes in children with operated cleft lip and palate

Information about the prevalence of consonant production errors, including compensatory articulations (CA), in individuals with cleft lip and palate (CLP) who speak Brazilian Portuguese is limited, particularly regarding liquid sounds. The literature primarily reports the occurrence of CA for plosive and fricative sounds, since occurrence of CAs in sounds that require higher amounts of oral air pressure is expected. While the use of CA during liquid sound production is not expected, clinical experience suggests that individuals with CLP present with inadequate backing, elevation, and anteriorization of the tongue as well as tongue clicks during production of /r/ and /l/.ObjectivesDescribe the occurrence of consonant error productions during liquid sounds for children with CLP; compare the occurrence between children operated with the Furlow and von Langenbeck techniques for palatoplasty; and compare the occurrence between children operated between 9-12 months and 15-18 months of age at primary palatoplasty. Material and MethodsA sample of 397 children (237 males and 160 females) with operated unilateral CLP was studied. In this group, 163 underwent palatoplasty with the Furlow procedure and 234 with the modified von Langenbeck procedure. Age at palatoplasty was between 9 and 12 months for 189 children and between 15 and 18 months for 208 children. Data about production of /l/, /r/, /R/, /λ/ and consonant clusters /l/ and /r/ were obtained from speech pathology records. Speech pathologists registered the speech findings after an auditory-perceptual evaluation of the participants at the sixth year of age. ResultsThe use of middorsum palatal place (MDP) of production was identified for 2% of the sample. Tongue anteriorization of the /l/ production was observed for 55% of the children. No significant difference was found related to surgical technique, but children operated earlier developed the use of the consonant cluster /r/ sooner than children operated later (p=0.040). ConclusionWe found a low occurrence of use of cleft related CA during attempts of production of liquid phonemes, and the variable age at primary palatoplasty significantly interfered with the acquisition of consonant cluster /r/.

Speech therapy for compensatory articulations and velopharyngeal function: a case report

The objective of this study was to describe the process of intensive speech therapy for a 6-year-old child using compensatory articulations while presenting with velopharyngeal insufficiency (VPI) and a history of cleft lip and palate. The correction of VPI was temporarily done with a pharyngeal obturator since the child presented with very little movement of the pharyngeal walls during speech, compromising the outcome of a possible pharyngeal flap procedure (pharyngoplasty). The program of intensive speech therapy involved 3 phases, each for duration of 2 weeks incorporating 2 daily sessions of 50 minutes of therapy. A total of 60 sessions of intervention were done with the initial goal of eliminating the use of compensatory articulations. Evaluation before the program indicated the use of co-productions (coarticulations) of voiceless plosive and fricative sounds with glottal stops (simultaneous production of 2 places of productions), along with weak intraoral pressure and hypernasality, all compromising speech intelligibility. To address place of articulation, strategies to increase intraoral air pressure were used along with visual, auditory and tactile feedback, emphasizing the therapy target and the air pressure and airflow during plosive and fricative sound productions. After the first two phases of the program, oral place of articulation of the targets were achieved consistently. During the third phase, velopharyngeal closure during speech was systematically addressed using a bulb reduction program with the objective of achieving velopharyngeal closure during speech consistently. After the intensive speech therapy program involving the use of a pharyngeal obturator, we observed absence of hypernasality and compensatory articulation with improved speech intelligibility.

LyricSynchronizer: Automatic Synchronization System Between Musical Audio Signals and Lyrics

This paper describes a system that can automatically synchronize polyphonic musical audio signals with their corresponding lyrics. Although methods for synchronizing monophonic speech signals and corresponding text transcriptions by using Viterbi alignment techniques have been proposed, these methods cannot be applied to vocals in CD recordings because vocals are often overlapped by accompaniment sounds. In addition to a conventional method for reducing the influence of the accompaniment sounds, we therefore developed four methods to overcome this problem: a method for detecting vocal sections, a method for constructing robust phoneme networks, a method for detecting fricative sounds, and a method for adapting a speech-recognizer phone model to segregated vocal signals. We then report experimental results for each of these methods and also describe our music playback interface that utilizes our system for synchronizing music and lyrics.

Perception and production of English fricative sounds by advanced Korean EFL learners

This study explored the perception and production of English voiceless fricatives among advanced Korean EFL learners by conducting on-line experiments. Thirty two college students who had overall high English proficiency participated in the experiments and nonce words beginning with one of the voiceless fricatives /f/, /?/, /s/, and /?/ were used in the experiments. In particular, 48 pairs of English nonce words, 24 identical (e.g., findert-findert, thomber-thomber) and non-identical pairs (e.g., findert-thindert, thomber-fomber) each, were employed in the perception test and the same 24 nonce words (e.g., findert, thimbert, simbert, shipkin; fomber, thombul, sombul, sholtem) were used in the production test. The results showed the precedence of perception over production but no correlation between them, indicating that the learners’ perceptual deficiency of target fricatives was not necessarily tied to their production defect of those sounds or vice versa. Importantly, the results from the perception test revealed that the participants had a great difficulty with the /f/-/?/ contrast, as opposed to the /s/-/?/ contrast. The participants’ ability to contrast between /?/ and /s/ was relatively good, unlike findings of previous studies (Joh and Lee 2001). As for production, the participants had most difficulty with the interdental fricative / / followed by /f/, but they did not have much difficulty with /s/ or /?/. Even though the results of the production test are overall consistent with those of the perception test, some discrepancy was found especially in the perception and production of /f/ and /?/. Further, replacement patterns in production were analyzed in terms of phonetic and/or articulatory properties of the target sounds and the L1 phonemic inventory. Some implications for the teaching of fricative sounds were also drawn.

The Production of English Sounds by Early Learners with Different English Learning Experience

This study investigated the production of English stop and fricative sounds by conducting on-line experiments on three groups of Korean children with different English-learning experience. More specifically, to examine the effect of different L2 experience on L2 sound production, 23 Korean EFL children, 21 bilingual returnees, and 19 ESL children produced 32 English nonce words. Their average age was 9.3. Nonce words consisted of 8 stops and 24 voiceless fricatives beginning with either the alveolar stop /t/ or /d/ (e.g., tilwerk, tolmick, dilwerk, dolmick) or one of the fricatives /f/, /?/, /s/, and /?/ (e.g., findert ,thindert, simbert, shipkin; farbin ,tharbin, soltem, sholtem). The results showed that the learners’ different English-learning experience had an impact on the production of English sounds, as the ESL children outperformed the bilingual returnees, who in turn outperformed the EFL children. Moreover, the results indicated that target sounds’ manners and places of articulation and the following vowel contexts influenced the production of English consonants by the children. Further, different patterns of substitution were obtained depending on the children’s different L2 experience. L1 interference and markedness were also shown to play a role in the production of L2 sounds. The role of perception in L2 production and its implications for L2 production were also discussed.

Speaker verification using the spectral and time parameters of voice signal

The speaker verification is based on variations in formant frequencies at stationary fragments and transient processes of vowels, the spectral features of fricative sounds, and the duration of speech segments. The best features are chosen for each word from the fixed list of Russian numerals ranging from zero to nine. The password phrase is randomly generated by the system at each verification. The compensation for dynamic noise and the counteraction with respect to interference using the reproduction of the intercepted and recorded speech are provided by the repeated reproduction of several words. The total error probabilities for male and female voices are 0.006 and 0.025%, respectively, for 30 million tests, 429 speakers, and a maximum length of the password phrase of 10 words. Note that the probabilities of false identification and false rejection are almost equal.