Speech Sounds Research Articles

Childhood Listening and Associated Cognitive Difficulties Persist Into Adolescence.

Listening difficulty (LiD) refers to the challenges individuals face when trying to hear and comprehend speech and other sounds. LiD can arise from various sources, such as hearing sensitivity, language comprehension, cognitive function, or auditory processing. Although some children with LiD have hearing loss, many have clinically normal audiometric thresholds. To determine the impact of hearing and cognitive factors on LiD in children with a clinically normal audiogram, we conducted a longitudinal study. The Evaluation of Children's Listening & Processing Skills (ECLiPS), a validated and standardized caregiver evaluation tool, was used to group participants as either LiD or typically developing (TD). Our previous study aimed to characterize LiD in 6- to 13-year-old children during the project's baseline, cross-sectional phase. We found that children with LiD needed a higher signal-to-noise ratio during speech-in-speech tests and scored lower on all assessed components of the NIH Cognition Toolbox than TD children. The primary goal of this study was to examine if the differences between LiD and TD groups are temporary or enduring throughout childhood. This longitudinal study had three data collection waves for children with LiD and TD aged 6 to 13 years at Wave 1, followed by assessments at 2-year (Wave 2) and 4-year (Wave 3) intervals. Primary analysis focused on data from Waves 1 and 2. Secondary analysis encompassed all three waves despite high attrition at Wave 3. Caregivers completed the ECLiPS, while participants completed the Listening in Spatialized Noise-Sentences (LiSN-S) test and the NIH-Toolbox Cognition Battery during each wave. The analysis consisted of (1) examining longitudinal differences between TD and LiD groups in demographics, listening, auditory, and cognitive function; (2) identifying functional domains contributing to LiD; and (3) test-retest reliability of measures across waves. Mixed-effect models were employed to analyze longitudinal data. The study enrolled 169 participants, with 147, 100, and 31 children completing the required testing during Waves 1, 2, and 3, respectively. The mean ages at these waves were 9.5, 12.0, and 14.0 years. On average, children with LiD consistently underperformed TD children in auditory and cognitive tasks across all waves. Maternal education, auditory, and cognitive abilities independently predicted caregiver-reported listening skills. Significant correlations between Waves 1 and 2 confirmed high, long-term reliability. Secondary analysis of Wave 3 was consistent with the primary analyses of Waves 1 and 2, reinforcing the enduring nature of listening difficulties. Children with LiD and clinically normal audiograms experience persistent auditory, listening, and cognitive challenges through at least adolescence. The degree of LiD can be independently predicted by maternal education, cognitive processing, and spatial listening skills. This study underscores the importance of early detection and intervention for childhood LiD and highlights the role of socioeconomic factors as contributors to these challenges.

What do you learn from a single cue? Dimensional reweighting and cue reassociation from experience with a newly unreliable phonetic cue

In language comprehension, we use perceptual cues to infer meanings. Some of these cues reside on perceptual dimensions. For example, the difference between bear and pear is cued by a difference in voice onset time (VOT), which is a continuous perceptual dimension. The present paper asks whether, and when, experience with a single value on a dimension behaving unexpectedly is used by the learner to reweight the whole dimension. We show that learners reweight the whole VOT dimension when exposed to a single VOT value (e.g., 45 ms) and provided with feedback indicating that the speaker intended to produce a /b/ 50% of the time and a /p/ the other 50% of the time. Importantly, dimensional reweighting occurs only if 1) the 50/50 feedback is unexpected for the VOT value, and 2) there is another dimension that is predictive of feedback. When no predictive dimension is available, listeners reassociate the experienced VOT value with the more surprising outcome but do not downweight the entire VOT dimension. These results provide support for perceptual representations of speech sounds that combine cues and dimensions, for viewing perceptual learning in speech as a combination of error-driven cue reassociation and dimensional reweighting, and for considering dimensional reweighting to be reallocation of attention that occurs only when there is evidence that reallocating attention would improve prediction accuracy (Harmon, Z., Idemaru, K., & Kapatsinski, V. 2019. Learning mechanisms in cue reweighting. Cognition, 189, 76–88.).

A Picture May Be Worth 1,000 Words, but Is It Worth a Letter? Examining Whether the Choice of Label Affects the Perception of Speech Sounds.

Researchers often use identification or goodness rating tasks to assess speech perception for different populations. These tasks provide useful information about a listener's willingness to accept a range of acoustically variable stimuli as belonging to the same category and also about assessing how stimuli that are labeled the same may not be perceived as equally good versions of a particular speech sound. Many methodological aspects of these simple tasks have been tested, but one aspect that has not is the choice of label. In this study, we examine response patterns to images versus letters, as studies with different populations (children vs. adults) or different methods (typical behavioral study vs. visual world paradigm) may vary in the type of label used. Eighty-one adult listeners completed phoneme identification and goodness ratings tasks with either images of response options (a picture of a bear and a picture of a pear) or with letter labels (a capital B and P). The results suggest that choice of label does not alter performance within the tasks studied here. In addition, the results did show the expected finding that the slope of the response curve is steeper in an identification task than in a goodness rating task. These results suggest that it is possible to compare across studies that use different response options, a benefit to research and practice because letter labels can be used for nonimageable words and nonwords, whereas images may be best used for participants who are younger or have poorer reading skills.

Correcting the record: Phonetic potential of primate vocal tracts and the legacy of Philip Lieberman (1934-2022).

The phonetic potential of nonhuman primate vocal tracts has been the subject of considerable contention in recent literature. Here, the work of Philip Lieberman (1934-2022) is considered at length, and two research papers-both purported challenges to Lieberman's theoretical work-and a review of Lieberman's scientific legacy are critically examined. I argue that various aspects of Lieberman's research have been consistently misinterpreted in the literature. A paper by Fitch et al.overestimates the would-be "speech-ready"capacities of a rhesus macaque, and the data presented nonetheless supports Lieberman's principal position-that nonhuman primates cannot articulate the full extent of human speech sounds. The suggestion that no vocal anatomical evolution was necessary for the evolution of human speech (as spoken by all normally developing humans) is not supported by phonetic or anatomical data. The second challenge, by Boë et al., attributes vowel-like qualities of baboon calls to articulatory capacities based on audio data; I argue that such "protovocalic"properties likely result from disparate articulatory maneuvers compared to human speakers. A review of Lieberman's scientific legacy by Boë et al.ascribes a view of speech evolution (which the authors term "laryngeal descent theory") to Lieberman, which contradicts his writings. The present article documents a pattern of incorrect interpretations of Lieberman's theoretical work in recent literature. Finally, the apparent trend of vowel-like formant dispersions in great ape vocalization literature is discussed with regard to Lieberman's theoretical work. The review concludes that the "Lieberman account"of primate vocal tract phonetic capacities remains supported by research: the ready articulation of fully human speech reflects species-unique anatomy.

The Perspectives of Students on the Role of Instructors' Facemasks in Hindering the Oral Communication Skills of Students Learning English at PYD, PSAU in the KSA

The present study aims to find out the impact of instructors' facemasks in hindering oral communication skills among students by investigating the factors that lead to such a hindrance in language learning and suggesting suitable solutions for reducing the negative effects of wearing facemasks and bettering communication skills. Findings indicate that, though wearing a facemask is mandatory for personal health and prevention against COVID-19, it hinders the students from developing their oral communication skills and prevents them from observing the facial expressions of English instructors that are hidden behind those facemasks. Tone and pitch are very essential in the process of oral communication and the changing of speech sounds is helpful to maintain oral communication speech channels. Nonetheless, it was observed that transparent facemask solves the problems of hiding facial and verbal expressions of the lips, and the video lessons compensate for the oral communication weaknesses of students. In view of the findings, it was therefore recommended that wearing a transparent facemask along with providing students with extra video lessons can be effective in helping students improve their oral communication skills.

The application of neuronavigated rTMS of the supplementary motor area and rhythmic speech training for stuttering intervention.

Stuttering, a neurodevelopmental speech fluency disorder, is associated with intermittent disruptions of speech-motor control. Behavioural treatments for adults who stutter (AWS) concentrate on adopting speech patterns that enhance fluency, such as speaking rhythmically or prolonging speech sounds. However, maintaining these treatment benefits can be challenging. Neuroimaging studies suggest that supplementary motor area (SMA) which play a crucial role in speech initiation, planning and internal timing shows aberrant activation in speech production of AWS and may contribute to stuttering. Preliminary evidence suggests that brain stimulation may impact responsiveness to behavioural treatments. The present study aims to investigate whether excitatory repetitive transcranial magnetic stimulation (rTMS) of the SMA and rhythmic speech can consistently reduce stuttering severity across various measures. Ten self-identified Cantonese-speaking AWS participated in this double-blinded, sham-controlled clinical trial study (NCT05472181). The participants underwent 10 sessions of rhythmic speech training across two phases, combined with either neuronavigated rTMS or sham, with a 2-week washout period between phases. The stuttering severity was assessed through various outcome measures, including the percentage of syllables stuttered, self-perceived stuttering severity, and the brief version of Unhelpful Thoughts and Beliefs About Stuttering before and after each treatment phase. Results demonstrated improved speech fluency in various speaking contexts, with no significant difference between rTMS and sham conditions immediately and 1 week post-treatment. Notably, rTMS specifically led to less stuttering in tongue twister production (d = -0.70). Both treatment conditions effectively reduced self-perceived stuttering severity and negative thoughts and beliefs about stuttering. The findings of this study indicate that stimulating the SMA reduced stuttering, only in the production of tongue twisters that may require greater motor control and coordination. Furthermore, it indicates that rhythmic speech might help alleviate negative beliefs and anxiety related to stuttering. This research contributes to our understanding of neuromodulation in stuttering treatment and the role of the SMA in speech motor control and emphasises the need for more research on the potential benefits and limitations of applying rTMS in this condition. What is already known on the subject Behavioural treatments for adults who stutter concentrate on adopting speech patterns that enhance fluency, such as speaking rhythmically or prolonging speech sounds. However, maintaining these treatment benefits can be challenging. Neuroimaging studies indicate that aberrant neural activation in speech production regions, like the supplementary motor area (SMA), is involved in stuttering. The SMA plays a crucial role in initiating, planning, and sequencing motor behaviours. Preliminary evidence suggests that brain stimulation (e.g., transcranial direct current stimulation or transcranial magnetic stimulation) may impact responsiveness to behavioural treatments. What this paper adds to existing knowledge There is limited knowledge regarding the potential effects of stimulating the SMA to enhance speech fluency in people who stutter. Existing research primarily consists of single case studies that lack proper control conditions or involve only a single stimulation session. Due to their limited scope and power, these studies may not provide sufficient evidence. The current study expands upon existing research by investigating whether multiple sessions of repetitive transcranial magnetic stimulation over the SMA, combined with rhythmic speech, improve speech fluency in adults who stutter. Furthermore, it addresses the limitations of brain stimulation methods and proposes directions for future research. What are the potential or actual clinical implications of this work? This study implies that the stimulation of SMA reduced stuttering only in speaking contexts that may require greater motor control and coordination such as tongue twisters. Additionally, the research suggests that using rhythmic speech could potentially alleviate negative beliefs and anxiety associated with stuttering.

What's special about human speech? A student exercise for comparing speech production between humans and chimpanzees.

Modern humans and chimpanzees share a common ancestor on the phylogenetic tree, yet chimpanzees do not spontaneously produce speech or speech sounds. The lab exercise presented in this paper was developed for undergraduate students in a course entitled "What's Special About Human Speech?" The exercise is based on acoustic analyses of the words "cup" and "papa" as spoken by Viki, a home-raised, speech-trained chimpanzee, as well as the words spoken by a human. The analyses allow students to relate differences in articulation and vocal abilities between Viki and humans to the known anatomical differences in their vocal systems. Anatomical and articulation differences between humans and Viki include (1) potential tongue movements, (2) presence or absence of laryngeal air sacs, (3) presence or absence of vocal membranes, and (4) exhalation vs inhalation during production.

한국어교육학과 언어병리학 그리고 청각학의 학문 간 융합 연구 시론

In order to expand the research area of Korean language pedagogy, this paper attempted to explore convergence research tasks with academic fields that have the commonality of Korean, such as Speech-Language Pathology and auditory studies. Speech-Language pathology is essentially an academic field that seeks ways to solve problems for people who have communication problems. Audiology is also an academic field that focuses on how to overcome communication difficulties using speech sounds based on the perception characteristics of speech sounds. As such, the need for convergence research to solve tasks that are difficult to solve independently in each academic field is great in that they are interested in the nature of Korean and its usage patterns. In the field of Speech-Language Pathology, in order to solve problems related to language development, standards for accurately measuring the degree of language development and treating people with delayed development or disabilities are needed. Although there is a need for convergence research with the Korean Language Pedagogy on how to prepare standards and guide language functions such as reading, writing, speaking, and listening, as well as essential vocabulary and grammar dlements used in everyday life, according to age and school age, such research has not been sufficiently conducted. There is no standard for treating this because it does not clearly present clear standards for language ability development, and it is difficult to present appropriate and effective educational methods in terms of educational methodology. In this regard, it was argued that future research on the development and rehabilitation methods of language development diagnostic tools should be conducted. In the field of Audiology, research related to the development of speech perception test tools is needed. For full communication, it is necessary to develop a tool that can test the communication ability of words, phrases, sentences, and discourse units beyond the stimulation of speech sounds at the phoneme level. Although there are differences in educational methods depending on the subject of education, linguistic pathology, and audiology, the fundamental content of education is very large. In the case of researchers, there may be a tendency to think that Korean language pedagogy has conducted relatively more research related to the characteristics of the Korean language than speech-language pathology and audiology. However, it is necessary to acknowledge that the research results on the nature of the Korean language required by neighboring disciplines are insignificant, and to conduct research to identify the nature and usage patterns of the Korean language through communication and cooperation with neighboring disciplines.

A theory that never was: Wrong way to the “Dawn of speech”

Recent literature argues that a purportedly long-standing theory—so-called “laryngeal descent theory”—in speech evolution has been refuted (Boë et al., 2019, https://doi.org/10.1126/sciadv.aaw3916). However, an investigation into the relevant source material reveals that the theory described has never been a prominent line of thinking in speech-centric sciences. The confusion arises from a fundamental misunderstanding: the argument that the descent of the larynx and the accompanying changes in the hominin vocal tract expanded the range of possible speech sounds for human ancestors (a theory that enjoys wide interdisciplinary support) is mistakenly interpreted as a belief that all speech was impossible without such changes—a notion that was never widely endorsed in relevant literature. This work aims not to stir controversy but to highlight important historical context in the study of speech evolution.

Pars Opercularis Underlies Efferent Predictions and Successful Auditory Feedback Processing in Speech: Evidence From Left-Hemisphere Stroke

Abstract Hearing one’s own speech allows for acoustic self-monitoring in real time. Left-hemisphere motor planning regions are thought to give rise to efferent predictions that can be compared to true feedback in sensory cortices, resulting in neural suppression commensurate with the degree of overlap between predicted and actual sensations. Sensory prediction errors thus serve as a possible mechanism of detection of deviant speech sounds, which can then feed back into corrective action, allowing for online control of speech acoustics. The goal of this study was to assess the integrity of this detection–correction circuit in persons with aphasia (PWA) whose left-hemisphere lesions may limit their ability to control variability in speech output. We recorded magnetoencephalography (MEG) while 15 PWA and age-matched controls spoke monosyllabic words and listened to playback of their utterances. From this, we measured speaking-induced suppression of the M100 neural response and related it to lesion profiles and speech behavior. Both speaking-induced suppression and cortical sensitivity to deviance were preserved at the group level in PWA. PWA with more spared tissue in pars opercularis had greater left-hemisphere neural suppression and greater behavioral correction of acoustically deviant pronunciations, whereas sparing of superior temporal gyrus was not related to neural suppression or acoustic behavior. In turn, PWA who made greater corrections had fewer overt speech errors in the MEG task. Thus, the motor planning regions that generate the efferent prediction are integral to performing corrections when that prediction is violated.

Comparative analysis of vowels in the phonological system of english, karakalpak and uzbek

In this article we try to explore the fundamental branch of linguistics that delves into the intricate structure of speech sounds, syllables, stress patterns, and intonation within a language. Phonetics is unique among linguistic disciplines as it not only investigates the linguistic function but also delves into the physical aspects of speech production, including the workings of the pronunciation apparatus and the acoustic properties of sound phenomena, as well as their interpretation by native speakers. Unlike non-linguistic fields, phonetics regards sound phenomena as integral components of a language system, essential for the transformation of words and sentences into audible forms crucial for communication. Phonetics considers both the acoustic-articulatory and functional-linguistic aspects of the sound system, thus distinguishing between phonetics proper and phonology. In essence, phonetics serves as a bridge between the abstract structures of language and their tangible manifestation in speech. It analyzes how sounds are produced by the human vocal tract, how they are perceived by listeners, and how they contribute to the overall meaning and communication process.

BiLSTM-CNN with fixed weight approach for tracking speech articulatory features

Speech production is a complex sequential process which involve the coordination of various articulatory features. Among them tongue being a highly versatile active articulator responsible for shaping airflow to produce targeted speech sounds that are intellectual, clear, and distinct. This paper presents a novel approach for predicting tongue and lip articulatory features involved in a given speech acoustics using a stacked Bidirectional Long Short-Term Memory (BiLSTM) architecture, combined with a one-dimensional Convolutional Neural Network (CNN) for post-processing with fixed weights initialization. The proposed network is trained with two datasets consisting of simultaneously recorded speech and Electromagnetic Articulography (EMA) datasets, each introducing variations in terms of geographical origin, linguistic characteristics, phonetic diversity, and recording equipment. The performance of the model is assessed in Speaker Dependent (SD), Speaker Independent (SI), corpus dependent (CD) and cross corpus (CC) modes. Experimental results indicate that the proposed model with fixed weights approach outperformed the adaptive weights initialization with in relatively minimal number of training epochs. These findings contribute to the development of robust and efficient models for articulatory feature prediction, paving the way for advancements in speech production research and applications.

Diagnosis of Autism in School Age and Adolescence in an Ethnically Diverse Population.

Despite policy emphasis on early identification, many children with Autism are diagnosed late, with some being diagnosed as late as adolescence. The objective of this study was to examine the demographics and clinical characteristics of school-age children and adolescents initially diagnosed with Autism age 7 and older, in an urban, university-affiliated multidisciplinary center that evaluates/treats youth with developmental disabilities. A chart review of all school-age children and adolescents referred for evaluation to determine if the child has developmental disabilities from January 2019 to May 2023 was performed. Of all children evaluated in that period (n = 825), 164 (19.8%) were diagnosed with Autism, 123 (75%) had a previous diagnosis, and 41 (25%) were newly diagnosed with Autism. Patients newly diagnosed with Autism age ≥7 were more likely to be diagnosed with Language Disorder (100% vs. 82%, p = 0.001) and Anxiety Disorder (27% vs. 13%, p = 0.04), be prescribed with an antidepressant (10% vs. 1%, p = 0.03), and less likely to be diagnosed with Intellectual Disabilities (13% vs. 34%, p = 0.001) than those who had a previous diagnosis of Autism, with no other differences in demographics or developmental diagnosis between the groups. Of the 136 patients referred for evaluation with a previous diagnosis of Autism, 13 (9.5%) did not meet the criteria for Autism any longer after multidisciplinary evaluations but continued to present developmental disorders, including Language Disorder (100%), attention-deficit/hyperactivity disorder (46%), and Speech Sound Disorder (38%). Of the 87 families who were concerned about Autism (without a previous diagnosis), 32 (36.8%) confirmed the diagnosis of Autism, 9 (1.5%) patients were newly diagnosed with Autism, and there were no parental concerns. In conclusion, in this ethnically diverse group of school-age children and adolescents with developmental disabilities, 25% received an initial diagnosis of Autism after age 7. Similar to previous reports, children who received a later diagnosis were more likely to present a language impairment, anxiety, and higher cognitive skills. Longitudinal studies, in ethnically diverse populations, are necessary to understand the trajectory and clinical profile of Autism.

The impact of face coverings on audio-visual contributions to communication with conversational speech

The use of face coverings can make communication more difficult by removing access to visual cues as well as affecting the physical transmission of speech sounds. This study aimed to assess the independent and combined contributions of visual and auditory cues to impaired communication when using face coverings. In an online task, 150 participants rated videos of natural conversation along three dimensions: (1) how much they could follow, (2) how much effort was required, and (3) the clarity of the speech. Visual and audio variables were independently manipulated in each video, so that the same video could be presented with or without a superimposed surgical-style mask, accompanied by one of four audio conditions (either unfiltered audio, or audio-filtered to simulate the attenuation associated with a surgical mask, an FFP3 mask, or a visor). Hypotheses and analyses were pre-registered. Both the audio and visual variables had a statistically significant negative impact across all three dimensions. Whether or not talkers’ faces were visible made the largest contribution to participants’ ratings. The study identifies a degree of attenuation whose negative effects can be overcome by the restoration of visual cues. The significant effects observed in this nominally low-demand task (speech in quiet) highlight the importance of the visual and audio cues in everyday life and that their consideration should be included in future face mask designs.

Speech Sounds Production, Narrative Skills, and Verbal Memory of Children with 22q11.2 Microdeletion.

22q11.2 deletion syndrome (22q11.2DS), the most frequent microdeletion syndrome in humans, is related to a high risk of developing neurodevelopmental disorders. About 95% of patients with 22q11.2DS have speech and language impairments. Global articulation, story generation, and verbal memory tests were applied to compare articulatory characteristics of speech sounds, spontaneous language abilities, and immediate verbal memory between four groups of Serbian-speaking children: patients with 22q11.2DS, children with clinical presentation of 22q11.2DS that do not have the microdeletion, children with non-syndromic congenital heart defects, and their peers with typical speech-sound development. The obtained results showed that children with this microdeletion have impaired articulation skills and expressive language abilities. However, we did not observe weaker receptive language skills and immediate verbal memory compared to healthy controls. Children with 22q11.2DS should be considered a risk category for the development of speech-sound pathology and expressive language abilities. Since speech intelligibility is an instrument of cognition and adequate peer socialization, and language impairment in school-aged children with 22q11DS might be an indicator of increased risk for later psychotic symptoms, patients with 22q11.2 microdeletion should be included in a program of early stimulation of speech-language development immediately after diagnosis is established.

Full Transfer and Segmental Emergence in the L2 Acquisition of Phonology: A Case Study

In this paper, we discuss a child Kazakh speaker’s acquisition of English as her second language. In particular, we focus on this child’s development of the English segments |f, v, θ, ð, ɹ, ʃ, ʧ|, which are not part of the Kazakh phonological inventory of consonants. We begin with a longitudinal description of the patterns that the child displayed through her acquisition of each of these segments. The data reveal patterns that range from extremely rapid to rather slow and progressive acquisition. The data also reveal patterns that were unexpected at first, for example, the slow development of |ʧ| in syllable onsets, an affricate that occurs as a contextual allophone in syllable onsets in Kazakh. We analyze these patterns through the Phonological Interference hypothesis, which was recently extended into the Feature Redistribution and Recombination hypothesis. These models predict the transfer into the L2 of all of the relevant phonological features present within the learner’s first language and their recombination to represent segments present in the L2. We also discuss contexts where feature-based approaches to L2 acquisition fail to capture the full range of observations. In all such contexts, we show that the facts are modulated by phonetic characteristics of the speech sounds present in either the child’s L1 or her L2.

Print-Rich Speech Sound Therapy Sessions: The Theory Behind It and Plans for Implementation

Purpose: Print knowledge is a powerful predictor of later reading abilities, which are crucial to children's academic success. Children with speech sound disorders (SSDs) are at risk for literacy difficulties. Speech sound therapy is an opportune time to address not only speech sound production but also the connections between speech sounds and their associated letters and letter patterns. This tutorial aims to provide a rich source of evidence to support the use of print and print-referencing in speech sound therapy sessions. We include feasible suggestions for speech-language pathologists (SLPs) to facilitate print-rich experiences for children with SSDs. Incorporating orthography into therapy sessions, through activities such as shared book reading, allows SLPs to address speech sound errors while supporting children's literacy development. Conclusions: This tutorial provides an overview of the risk of literacy deficits in children with SSDs and describes the theoretical underpinnings of why incorporating print is a powerful learning tool. We expand on the research behind print referencing in preschool classrooms. Finally, we provide detailed examples, including book lists and therapy ideas for a variety of ages, to help SLPs add print referencing to their therapy toolkit.

Speech Sound Disorders of Children With Mental Delays

This study aimed to investigate the speech sounds processes of children diagnosed with mental delays. Additionally, we explored all the sounds of the Albanian language, in level of articulation. We recruited 50 children, including 25 boys and 25 girls, with a mean age of 7.68 years. The results support the hypothesis that children diagnosed with mental delays are prone to speech sounds difficulties. Therefore, emphasizing the importance of possible risks in communication level is needed in order to address the needs of children with mental delays. Finally, this study is one of the first that investigated the phenomena of speech sounds difficulties in children with mental delays in Kosovar context.

Method for asynchronous analysis of a glottal source based on a two-level autoregressive model of the speech signal

The task of analyzing a glottal source over a short observation interval is considered. The acute problem of insufficient performance of known methods for analyzing a glottal source is pointed out, regardless of the mode of data preparation: synchronous with the main tone of speech sounds or asynchronous. A method for analyzing the glottal source based on a two-level autoregressive model of the speech signal is proposed. Its software implementation based on the high-speed Burg-Levinson computational procedure is described. It does not require synchronization of the sequence of observations used with the main tone of the speech signal and is characterized by a relatively small amount of computational costs. Using the described software implementation, a full-scale experiment was set up and conducted, where the vowel sounds of the control speaker’s speech were used as the object of study. Based on the results of the experiment, the increased performance of the proposed method was confirmed and its requirements for the duration of the speech signal during voice analysis in real time were formulated. It is shown that the optimal duration is in the range from 32 to 128 ms. The results obtained can be used in the development and research of digital speech communication systems, voice control, biometrics, biomedicine and other speech systems where the voice characteristics of the speaker’s speech are of paramount importance.

Ciluba Speaking Learners’ Interference in Sound Production

This study addresses interference produced by Cilubà speaking learners in their English learning process in the classroom (in some schools of Mbujimayi). It aims at providing some hints which are likely to help overcome such difficulties of language learners use English with some connected speech sounds. Observation and questionnaires (interviews) are approaches used to collect and interpret the data. After investigation, the study has proved that there are three types of sounds interference learners’ levels, namely grouped as Higher interference users (75% of 80 learners observed); Intermediate level learners (36% of 125 learners observed); and Advanced level learners (25% of 42 learners observed). Some remedies should be taken into consideration like, intensification of reading tasks, the allotment of more time to oral tasks than to written ones by making learners talk more and more, the focus on learners’ pronunciation problems for some items containing complex vowel sounds, training learners how to discriminate sounds they cross enough difficulties, and helping them to have more practice on spelling exercises.