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The underwater soundscape was recorded in Seaview Bay off Inexpressible Island, Ross Sea region Marine protected area, for 3 days in December 2021. Leopard seal Hydrurga leptonyx vocalizations were a prominent sound source that led to variations in ambient sound pressure levels in a frequency range of approximately 150-4500 Hz. Among the 14 call types previously identified, except ultrasound vocalizations, six types of broadcast calls were classified, and their acoustic characteristics were analyzed. We focused on the acoustic characteristics of four low-frequency calls, clustered in a relatively narrow bandwidth, which have been relatively less studied. We identified a new call type of a triple ascending trill consisting of three trill parts, expanding upon the findings of previous studies. The audio data extracted from leopard seal vocalization videos, recorded by a monitoring camera on sea ice, enhanced the reliability of identifications of the underwater triple ascending trill. We present the unique results of underwater passive acoustic monitoring conducted at Seaview Bay, designated as Antarctic Specially Protected Area No 178. Our results could contribute to the development of detection and localization algorithms for leopard seal vocalizations and can be used as fundamental data for studies related to the vocalization and behavior of this species.

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To address the requirements of sonar imaging, such as high receiving sensitivity, a wide bandwidth, and a wide receiving angle, an AlN PMUT with an optimized ratio of 0.6 for the piezoelectric layer diameter to backside cavity diameter is proposed in this paper. A sample AlN PMUT is designed and fabricated with the SOI substrate-based bulk MEMS process. The characterization test result of the sample demonstrates a -6 dB bandwidth of approximately 500 kHz and a measured receiving sensitivity per unit area of 1.37 V/µPa/mm2, which significantly surpasses the performance of previously reported PMUTs. The -6 dB horizontal angles of the AlN PMUT at 300 kHz and 500 kHz are measured as 68.30° and 54.24°, respectively. To achieve an accurate prediction of its characteristics when being packaged and assembled in a receive array, numerical simulations with the consideration of film stress are conducted. The numerical result shows a maximum deviation of ±7% in the underwater receiving sensitivity across the frequency range of 200 kHz to 1000 kHz and a deviation of about 0.33% in the peak of underwater receiving sensitivity compared to the experimental data. By such good agreement, the simulation method reveals its capability of providing theoretical foundation for enhancing the uniformity of AlN PMUTs in future studies.

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The aim of this study was to quantitatively determine the acoustic characteristics of bedrooms in two types of long-term care facilities in China. Objective acoustic conditions, including noise levels and reverberation times, were measured through a series of acoustic measurements in twelve bedrooms in two nursing homes and three adult care homes in Kunming city, China. The impacts of noise and sound preferences were evaluated through a questionnaire survey administered to residents and nursing staff. In terms of the sound field, the background noise levels in most measured bedrooms exceeded the WHO's recommended value (30 dBA) by approximately 10-15 dBA. Compared to those in adult care homes, the noise levels in nursing homes were approximately 5-7 dBA higher during the daytime and 2-3 dBA higher during the nighttime due to frequent nursing activities. Moreover, noise levels were 5-15 dBA higher in roadside bedrooms. The reverberation time of five bedrooms reached 0.8 s at low frequency (125 Hz) due to their large space and absence of sound-absorbing materials. The questionnaire showed that noise sources were mainly perceived as coming from corridors and out-of-windows by residents and nursing staff. Traffic noise, residents' yelling in pain (just in nursing homes) and footsteps were considered the most noticeable noises, which may have had negative effects on participants' sleep quality, health, and emotional state. Moreover, the residents in roadside bedrooms reported that noise had a greater impact on their sleep (p < 0.01). Compared to artificial and mechanical sounds, participants preferred nature sounds, such as streams and birds, which were significantly (p < 0.01) positively correlated with age.

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Water distribution networks (WDNs) experience significant water loss due to leaks, necessitating advanced water leak detection methods. However, machine learning-based acoustic method heavily relies on signal information and is limited by data scarcity and the limited diversity of available data. To address this challenge and enhance water leak detection in WDNs, this study proposes an LSTM-GAN approach. Acoustic signals are collected from WDNs to train the LSTM-GAN model, which generates synthetic leak signals to enhance the dataset. The validity of the generative method is evaluated through t-SNE and acoustic characteristics analysis. LSTM-based water leak detection models are established and compared using the original and the generated datasets to confirm the efficacy of generated samples in improving water leak detection performances. The capability of LSTM-GAN has been evaluated through different perspectives, including sensitivity analysis and model comparison. The results validate the quality and consistency of the generated acoustic signals under leak conditions. Besides, the optimal number of generated samples should be determined according to the requirements and characteristics of the leak detection task. Furthermore, the comparison between the proposed method and other acoustic generative methods demonstrates the superiority of LSTM-GAN-generated signals in enhancing the performance of leak detection models. The proposed generative method offers an innovative approach to facilitate machine learning-based leak detection models with limited data, thereby enhancing robustness.

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The ossicular replacement prosthesis should have good biocompatibility, stability, easy to install, and excellent sound transmission capacity. In this study, the characteristics of ideal materials for the ossicular replacement prosthesis were analyzed by searching the types of materials used in clinical practice and comparing the advantages and disadvantages of various materials and structures. At the same time, in combination with the current evaluation requirements and evaluation experience, the focus of the performance research project of ossicular replacement prosthesis in the process of registration is discussed to clarify the performance evaluation requirements of these products, so as to provide reference for the future work of manufacturers and regulators. The performance evaluation of ossicular replacement prosthesis focuses on its mechanical properties, fixation stability, sound transmission characteristics, biological characteristics, and magnetic resonance compatibility.

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BACKGROUND: Teachers are professional voice users, and the vocal demands in the teaching profession can be considered unique. All teachers will wish to possess a voluminous, strongly-carrying voice that can be maintained for a prolonged time. This necessitated the need to understand and document the voice-acoustic characteristics of teachers. OBJECTIVES: The specific objectives were to (a) investigate the acoustic characteristics of teachers' voices, (b) compare voice acoustic characteristics between female and male teachers, and (c) compare acoustic characteristics of voice between teachers and nonteachers. PARTICIPANTS: Four hundred thirty-nine individuals congregated into two groups. Group 1 had 264 female teachers (mean age: 36.8 years) and 42 male teachers (mean age 36.8 years) with a minimum of 5 years of teaching experience. A hundred females (mean age: 37.3 years) and 33 males (mean age: 36.1 years) adults not indulging in additional, prolonged use of voice were in group 2. MATERIALS AND METHOD: Sustenance of vowel /a/ for 3 seconds at a comfortable pitch and loudness followed by a monologue on "My school" for 1 minute were audio-recorded at the locations of the participants. Multidimensional Voice Profiles and Real Time Pitch were used to analyze the phonation and monologue samples, respectively. RESULTS: Revealed that most F0 and its related measures, short- and long-term frequency perturbations were higher in female compared to the male participants. The majority of the acoustic parameters were higher in teachers compared to nonteachers of both sexes. CONCLUSION: The results, in general, confirmed a few evinced findings in females and males, strengthening the nature-controlled biophysical influence on voice. A few acoustic measures discerned voices of teachers and nonteachers and also females and males in teachers. Nonteachers of both sexes showed better acoustic characteristics of voice against teachers signifying that the extended and prolonged voice use, an occupational demand of the teaching profession, led to vocal loading affecting the acoustic characteristics of teachers' voices.

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AIM: Drug use/addiction has a profound impact on the physical and mental health of individuals. Previous studies have indicated that drug users may experience speech perception disorders, including speech illusion and challenges in recognizing emotional speech. However, the influence of drugs on speech production, as another crucial aspect of speech communication, has not been thoroughly examined. Therefore, the current study aimed to investigate how drugs affect the acoustic characteristics of speech in Chinese male drug users. METHOD: Speech recordings were collected from a total of 160 male drug users (including 106 heroin users, 23 ketamine users, and 31 methamphetamine users) and 55 male healthy controls with no history of drug use. Acoustic analysis was conducted on the collected speech data from these groups, and classification analysis was performed using five supervised learning algorithms. RESULTS: The results demonstrated that drug users exhibited smaller F0 standard deviation, reduced loudness, cepstral peak prominence, and formant relative energies, as well as higher H1-A3, longer unvoiced segments, and fewer voiced segments per second compared to the control group. The classification analyses yielded good performance in classifying drug users and non-drug users, with an accuracy above 86%. Moreover, the identification of the three groups of drug users achieved an accuracy of approximately 70%. Additionally, the study revealed different effects on speech production among the three types of drugs. CONCLUSION: The above findings indicate the presence of speech disorders, such as vocal hoarseness, in drug users, thus confirming the assumption that the acoustic characteristics of speech in drug users deviates from the norm. This study not only fills the knowledge gap regarding the effects of drugs on the speech production of Chinese male drug users but also provides a more comprehensive understanding of how drugs impact human behaviors. Furthermore, this research provides theoretical foundations of detoxification and speech rehabilitation for drug users.

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This study aims to assess (i) which acoustic characteristics of snoring sounds are associated with the annoying nature of snoring sounds; (ii) whether listeners' heart rates correlate with their perceived annoyance; and (iii) whether perceived annoyance is different between listeners with different experiences with their bedpartners' snoring sounds. Six snoring epochs with distinct acoustic characteristics (viz., reference, high pitch, high intensity, short interval, irregular intensity, and irregular intervals) were collected from snoring patients. Twenty physicians and technicians were involved in the healthcare of snoring patients, and were divided into three groups based on personal experience with their bedpartners' snoring sounds (viz., non-snoring, snoring but not annoying, and snoring and annoying). The test subjects listened to each epoch and rated its level of annoyance. Listeners' heart rates were also recorded during the test using a finger plethysmograph. Within the limitations of this study, it was found that, compared with other snoring sounds, snoring sounds with high intensity and irregularity were associated with higher perceived annoyance. However, higher perceived annoyance of snoring sound was not reflected in heart rate-related parameters. In addition, listeners' personal experiences do not seem to affect their perceived annoyance.

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INTRODUCTION: A plethora of vocal enhancement and rehabilitation programs for voice professionals define vocal exercises irrespective of analyzing their effects on the specific population on which they are applied, in the established dose and often without considering the presence and absence of vocal alteration. So, in this study we investigated the impact of warm-up exercises (WUE) on the acoustic features of the gym coaches. OBJECTIVE: To determine the effectiveness of WUE on the acoustic characteristics of the voice in gym coaches. STUDY DESIGN: This was a Quasi-experimental control group design study. METHOD: The study was carried out through participation of forty-five female gym coaches with a mean age of 31.4 years (range: 19-44 years) in Mashhad gym salon. Participants were recruited into two conditions. In the first condition, participants did not receive the exercises for a week and were acoustically evaluated at the beginning and end of the week. In the second condition, participants received the exercises once a day for a week and were acoustically evaluated at the beginning and end of the week. Voice samples were included: at least 3 vowels / a / for at least five seconds. The voice samples analyzed by the Praat software recorder (Version 6.0.23) were collected to detect the acoustic characteristics of voice including fundamental frequency (f0) (Hz), jitter (%), shimmer (dB) and noise to harmonic ratio (NHR) (dB). Finally, the data obtained from these two condition were compared. RESULTS: After WUE, a significant increased f0, decreased jitter, decreased shimmer and decreased NHR were measured. (p-value < 0.005). CONCLUSION: The WUE had an immediate positive effect on acoustic characteristics of voice)f0, jitter, shimmer and NHR(in the short term and this study suggests that the WUE is an effective technique for enhancing the overall voice quality of gym coaches.

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The ossicular replacement prosthesis should have good biocompatibility, stability, easy to install, and excellent sound transmission capacity. In this study, the characteristics of ideal materials for the ossicular replacement prosthesis were analyzed by searching the types of materials used in clinical practice and comparing the advantages and disadvantages of various materials and structures. At the same time, in combination with the current evaluation requirements and evaluation experience, the focus of the performance research project of ossicular replacement prosthesis in the process of registration is discussed to clarify the performance evaluation requirements of these products, so as to provide reference for the future work of manufacturers and regulators. The performance evaluation of ossicular replacement prosthesis focuses on its mechanical properties, fixation stability, sound transmission characteristics, biological characteristics, and magnetic resonance compatibility.

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Italian vowels have a shorter duration before a geminate than before a singleton consonant, but a longer duration in syllables carrying stress. We asked whether children can produce the differentiation in vowel duration in singleton/geminate contexts reported for adults and whether their production changes depending on position of primary stress. Italian children (three-to-six-year-olds) and adults performed a nonword repetition. Each nonword appeared in four contexts, with the stressed/unstressed vowel preceding/following the singleton/geminate: /pa'paso/, /pap'paso/, 'papaso/, /'pappaso/. Acoustic analyses on the duration of the vowel preceding (V1) and following (V2) the medial consonant showed a type of consonant by age group interaction: the difference in vowel duration between children and adults was greater for geminate than singleton contexts, and was greater when the vowel carried stress. When V1 carried stress, its duration was shorter in the geminate than in the singleton in adults and older children, not in younger children.

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BACKGROUND:  Laryngopharyngeal reflux (LPR) is prevalent and can lead to voice disorders, but its diagnosis is difficult, because of limited correlations between clinical symptoms and organic pathology. Various tools and methods have been explored to aid a diagnosis of LPR. OBJECTIVE:  To investigate associations between reflux symptoms, acoustic-, perceptual-, and physical vocal characteristics, glottal function index (GFI), and vocal handicap index (VHI) in adults with non-organic voice disorders. METHODS:  Data of 51 adults with non-organic voice disorders were collected, using a retrospective cohort explorative research design, at a private ear, nose and throat specialist practice in Gauteng, South Africa. Quantitative outcomes were compared between reflux symptom index (RSI), acoustic characteristics (jitter, shimmer and fundamental frequency [F0]), maximum phonation time, perceptual- (GRBASI) and physical vocal characteristics, GFI and VHI. RESULTS:  The RSI showed positive fair correlations against GFI, VHIP and caffeine intake, indicating an increase in reflux symptoms with higher scores on the various measures. Moderate correlations were also found between GFI and VHIP, grade of hoarseness and jitter, strain and VHIP, strain and VHI total (VHIT) and between Asthenia and jitter. Very strong correlations were found within the various subsections of the VHI as well as between jitter and shimmer and between F0-male and physical symptoms of the VHI (VHIP). CONCLUSION:  Results indicated associations between reflux symptoms, vocal characteristics, the GFI and the VHI. Based on the correlations found these tools used in conjunction could improve clinical diagnosis of LPR. Implications of these findings are promising, but further research is recommended.Contribution: This study contributes to the body of knowledge to support the accurate clinical diagnosis of LPR using subjective measures to determine LPR symptoms, as well as acoustic analysis.

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Over the last two decades, several experimental and numerical studies have been performed in order to investigate the acoustic behavior of different muffler materials. However, there is a problem in which it is necessary to perform large, important, time-consuming calculations particularly if the muffler was made from advanced materials such as composite materials. Therefore, this work focused on developing the concept of the indirect dual-chamber muffler made from a basalt fiber reinforced polymer (BFRP) laminated composite, which is a monitoring system that uses a deep learning algorithm to predict the acoustic behavior of the muffler material in order to save effort and time on muffler design optimization. Two types of deep neural networks (DNNs) architectures are developed in Python. The first DNN is called a recurrent neural network with long short-term memory blocks (RNN-LSTM), where the other is called a convolutional neural network (CNN). First, a dual-chamber laminated composite muffler (DCLCM) model is developed in MATLAB to provide the acoustic behavior datasets of mufflers such as acoustic transmission loss (TL) and the power transmission coefficient (PTC). The model training parameters are optimized by using Bayesian genetic algorithms (BGA) optimization. The acoustic results from the proposed method are compared with available experimental results in literature, thus validating the accuracy and reliability of the proposed technique. The results indicate that the present approach is efficient and significantly reduced the time and effort to select the muffler material and optimal design, where both models CNN and RNN-LSTM achieved accuracy above 90% on the test and validation dataset. This work will reinforce the mufflers' industrials, and its design may one day be equipped with deep learning based algorithms.

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The nitrogen-vacancy (NV) center of the diamond has attracted widespread attention because of its high sensitivity in quantum precision measurement. The phonon piezoelectric device of the NV center is designed on the basis of the phonon-coupled regulation mechanism. The propagation characteristics and acoustic wave excitation modes of the phonon piezoelectric device are analyzed. In order to improve the performance of phonon-coupled manipulation, the influence of the structural parameters of the diamond substrate and the ZnO piezoelectric layer on the phonon propagation characteristics are analyzed. The structure of the phonon piezoelectric device of the NV center is optimized, and its Micro-Electro-Mechanical System (MEMS) implementation and characterization are carried out. Research results show that the phonon resonance manipulation method can effectively increase the NV center's spin transition probability using the MEMS phonon piezoelectric device prepared in this paper, improving the quantum spin manipulation efficiency.

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OBJECTIVE: As Alzheimer's disease (AD) might provoke certain nerve disorders, patients with AD can acquire sensorimotor adaptation problems, and thus the acoustic characteristics of the speech they produce may differ from those of healthy subjects. This study aimed to (1) extract acoustic characteristics (relating to articulatory gestures) potentially useful for detecting AD and (2) examine whether these characteristics could help identify AD patients. METHODS: A total of 50 individuals participated in the study, including the AD group (17 cases), the Neurologically Healthy (NH) group (13 cases), the Mild Cognitive Impairment (MCI) group (11 cases), and the Vascular Cognitive Impairment (VCI) group (9 cases). Voice samples involving three vowels (/i/, /a/, and /u/) and six consonants (/p/, /pÊ°/, /t/, /tÊ°/, /k/, and /kÊ°/) were collected using a digital recorder (TASCAM DR40X). Microphone-to-mouth distance was maintained at 30 cm. Acoustic measures included F0, jitter, shimmer, HNR, F1, F2, F3, and VOT. RESULTS: One-way ANOVA tests were carried out to compare the acoustic measures among the four groups. F3 of vowel /u/, F2 bandwidth of vowel /a/, VOT of consonant /t/, and male participants' F0 of three vowels (/a/, /i/, and /u/) were found significantly different, while no significant differences were found in the other measures. CONCLUSION: Some acoustic characteristics can indeed help detect AD patients.

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Background: At present, there is no established biomarker for the diagnosis of depression. Meanwhile, studies show that acoustic features convey emotional information. Therefore, this study explored differences in acoustic characteristics between depressed patients and healthy individuals to investigate whether these characteristics can identify depression. Methods: Participants included 71 patients diagnosed with depression from a regional hospital in Beijing, China, and 62 normal controls from within the greater community. We assessed the clinical symptoms of depression of all participants using the Hamilton Depression Scale (HAMD), Hamilton Anxiety Scale (HAMA), and Patient Health Questionnaire (PHQ-9), and recorded the voice of each participant as they read positive, neutral, and negative texts. OpenSMILE was used to analyze their voice acoustics and extract acoustic characteristics from the recordings. Results: There were significant differences between the depression and control groups in all acoustic characteristics (p < 0.05). Several mel-frequency cepstral coefficients (MFCCs), including MFCC2, MFCC3, MFCC8, and MFCC9, differed significantly between different emotion tasks; MFCC4 and MFCC7 correlated positively with PHQ-9 scores, and correlations were stable in all emotion tasks. The zero-crossing rate in positive emotion correlated positively with HAMA total score and HAMA somatic anxiety score (r = 0.31, r = 0.34, respectively), and MFCC9 of neutral emotion correlated negatively with HAMD anxiety/somatization scores (r = -0.34). Linear regression showed that the MFCC7-negative was predictive on the PHQ-9 score (ß = 0.90, p = 0.01) and MFCC9-neutral was predictive on HAMD anxiety/somatization score (ß = -0.45, p = 0.049). Logistic regression showed a superior discriminant effect, with a discrimination accuracy of 89.66%. Conclusion: The acoustic expression of emotion among patients with depression differs from that of normal controls. Some acoustic characteristics are related to the severity of depressive symptoms and may be objective biomarkers of depression. A systematic method of assessing vocal acoustic characteristics could provide an accurate and discreet means of screening for depression; this method may be used instead of-or in conjunction with-traditional screening methods, as it is not subject to the limitations associated with self-reported assessments wherein subjects may be inclined to provide socially acceptable responses rather than being truthful.

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This study examined acoustic characteristics of the phoneme /l/ produced by young female and male adult speakers of Southern White Vernacular English (SWVE) from Louisiana. F1, F2, and F2-F1 values extracted at the /l/ midpoint were analyzed by word position (pre- vs. post-vocalic) and vowel contexts (/i, ɪ/ vs. /ɔ, a/). Descriptive analysis showed that SWVE /l/ exhibited characteristics of the dark /l/ variant. The formant patterns of /l/, however, differed significantly by word position and vowel context, with pre-vocalic /l/ showing significantly higher F2-F1 values than post-vocalic /l/, and /l/ in the high front vowel context showing significantly higher F2-F1 values than those in the low back vowel context. Individual variation in the effects of word position and vowel contexts on /l/ pattern was also observed. Overall, the findings of the current study showed a gradient nature of SWVE /l/ variants whose F2-F1 patterns generally fell into the range of the dark /l/ variant, while varying by word position and vowel context.

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PURPOSE: The current study examined acoustic characteristics of English /l/ produced by Korean speakers who speak English as their second language (KE). Comparisons were made to patterns of their Korean /l/ and English /l/ produced by monolingual speakers of American English (AE). Vowel context and word position effects on acoustic differences among the three /l/ sounds were examined in relation to the degree of foreign accentedness of KE speakers. METHODS: Korean and English word-initial and -final /l/ in two vowel contexts (high front vs. low back) were produced by 12 KE female adult speakers in a carrier phrase. A comparison group of 10 AE speakers produced English /l/. F1 and F2 values of each /l/ production were extracted at the /l/ midpoint and were compared to each other. Euclidean distances across the productions were also examined in relation to the degrees of foreign accentedness of KE speakers. RESULTS: KE speakers' English /l/ showed significantly lower F2-F1 values than their Korean /l/ across word position and vowel context but significantly higher F2-F1 values than AE speakers' English word-initial /l/. Euclidean distance between KE speakers' English and Korean /l/, and KE and AE speakers' English /l/ correlated significantly with KE speakers' degree of foreign accentedness across word position and vowel context. CONCLUSION: Results indicate that the influence of Korean on KE speakers' English /l/ productions varied by word position and vowel context, as well as the degree of their foreign accentedness ratings. This finding suggests the context-dependent nature of /l/ productions and highlights the need for considering a speakers' degree of foreign accent when exploring English /l/ patterns of KE speakers.

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The vibrational behavior of an underwater structure in the free field is different from that in bounded noisy environments because the fluid-structure interaction is strong in the water and the vibration of the structure caused by disturbing fields (the reflections by boundaries and the fields radiated by sources of disturbances) cannot be ignored. The conventional free field recovery (FFR) technique can only be used to eliminate disturbing fields without considering the difference in the vibrational behavior of the structure in the free field and the complex environment. To recover the free-field acoustic characteristics of a structure from bounded noisy underwater environments, a method combining the boundary element method (BEM) with the vibro-acoustic coupling method is presented. First, the pressures on the measurement surface are obtained. Second, the outgoing sound field and the rigid body scattered sound field are calculated by BEM. Then, the vibro-acoustic coupling method is employed to calculate the elastically radiated scattered sound field. Finally, the sound field radiated by the structure in the free field is recovered by subtracting the rigid body scattered sound field and the elastically radiated scattered sound field from the outgoing sound field. The effectiveness of the proposed method is validated by simulation results.

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This study examined the development of vowel categories in young Mandarin -English bilingual children. The participants included 35 children aged between 3 and 4 years old (15 Mandarin-English bilinguals, six English monolinguals, and 14 Mandarin monolinguals). The bilingual children were divided into two groups: one group had a shorter duration (<1 year) of intensive immersion in English (Bi-low group) and one group had a longer duration (>1 year) of intensive immersion in English (Bi-high group). The participants were recorded producing one list of Mandarin words containing the vowels /a, i, u, y, ɤ/ and/or one list of English words containing the vowels /i, ɪ, e, ɛ, æ, u, ʊ, o, ɑ, ʌ/. Formant frequency values were extracted at five equidistant time locations (the 20-35-50-65-80% point) over the course of vowel duration. Cross-language and within-language comparisons were conducted on the midpoint formant values and formant trajectories. The results showed that children in the Bi-low group produced their English vowels into clusters and showed positional deviations from the monolingual targets. However, they maintained the phonetic features of their native vowel sounds well and mainly used an assimilatory process to organize the vowel systems. Children in the Bi-high group separated their English vowels well. They used both assimilatory and dissimilatory processes to construct and refine the two vowel systems. These bilingual children approximated monolingual English children to a better extent than the children in the Bi-low group. However, when compared to the monolingual peers, they demonstrated observable deviations in both L1 and L2.

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