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33 pages, 4142 KiB  
Review
Advances in Wettability-Engineered Open Planar-Surface Droplet Manipulation
by Ge Chen, Jin Yan, Junjie Liang, Jiajia Zheng, Jinpeng Wang, Hongchen Pang, Xianzhang Wang, Zihao Weng and Wei Wang
Micromachines 2025, 16(8), 893; https://doi.org/10.3390/mi16080893 (registering DOI) - 31 Jul 2025
Viewed by 324
Abstract
Firstly, this paper reviews the fundamental theories of solid surface wettability and contact angle hysteresis. Subsequently, it further introduces four typical wettability-engineered surfaces with low hysteresis (superhydrophobic, superamphiphobic, super-slippery, and liquid-like smooth surfaces). Finally, it focuses on the latest research progress in the [...] Read more.
Firstly, this paper reviews the fundamental theories of solid surface wettability and contact angle hysteresis. Subsequently, it further introduces four typical wettability-engineered surfaces with low hysteresis (superhydrophobic, superamphiphobic, super-slippery, and liquid-like smooth surfaces). Finally, it focuses on the latest research progress in the field of droplet manipulation on open planar surfaces with engineered wettability. To achieve droplet manipulation, the core driving forces primarily stem from natural forces guided by bioinspired gradient surfaces or the regulatory effects of external fields. In terms of bioinspired self-propelled droplet movement, this paper summarizes research inspired by natural organisms such as desert beetles, cacti, self-aligning floating seeds of emergent plants, or water-walking insects, which construct bioinspired special gradient surfaces to induce Laplace pressure differences or wettability gradients on both sides of droplets for droplet manipulation. Moreover, this paper further analyzes the mechanisms, advantages, and limitations of these self-propelled approaches, while summarizing the corresponding driving force sources and their theoretical formulas. For droplet manipulation under external fields, this paper elaborates on various external stimuli including electric fields, thermal fields, optical fields, acoustic fields, and magnetic fields. Among them, electric fields involve actuation mechanisms such as directly applied electrostatic forces and indirectly applied electrocapillary forces; thermal fields influence droplet motion through thermoresponsive wettability gradients and thermocapillary effects; optical fields cover multiple wavelengths including near-infrared, ultraviolet, and visible light; acoustic fields utilize horizontal and vertical acoustic radiation pressure or acoustic wave-induced acoustic streaming for droplet manipulation; the magnetic force acting on droplets may originate from their interior, surface, or external substrates. Based on these different transport principles, this paper comparatively analyzes the unique characteristics of droplet manipulation under the five external fields. Finally, this paper summarizes the current challenges and issues in the research of droplet manipulation on the open planar surfaces and provides an outlook on future development directions in this field. Full article
(This article belongs to the Special Issue Advanced Microfluidic Chips: Optical Sensing and Detection)
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13 pages, 3767 KiB  
Article
An Analysis of Audio Information Streaming in Georg Philipp Telemann’s Sonata in C Major for Recorder and Basso Continuo, Allegro (TWV 41:C2)
by Adam Rosiński
Arts 2025, 14(4), 76; https://doi.org/10.3390/arts14040076 - 14 Jul 2025
Viewed by 318
Abstract
This paper presents an analysis of G. P. Telemann’s Sonata in C Major for Recorder and Basso Continuo (TWV 41:C2, Allegro), with the aim of investigating the occurrence of perceptual streams. The presence of perceptual streams in musical works helps to organise [...] Read more.
This paper presents an analysis of G. P. Telemann’s Sonata in C Major for Recorder and Basso Continuo (TWV 41:C2, Allegro), with the aim of investigating the occurrence of perceptual streams. The presence of perceptual streams in musical works helps to organise the sound stimuli received by the listener in a specific manner. This enables each listener to perceive the piece in an individual and distinctive manner, granting primacy to selected sounds over others. Directing the listener’s attention to particular elements of the auditory image leads to the formation of specific mental representations. This, in turn, results in distinctive interpretations of the acoustic stimuli. All of these processes are explored and illustrated in this analysis. Full article
(This article belongs to the Special Issue Sound, Space, and Creativity in Performing Arts)
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27 pages, 3422 KiB  
Article
Audiovisual Perception of Sentence Stress in Cochlear Implant Recipients
by Hartmut Meister, Moritz Wächtler, Pascale Sandmann, Ruth Lang-Roth and Khaled H. A. Abdel-Latif
Audiol. Res. 2025, 15(4), 77; https://doi.org/10.3390/audiolres15040077 - 24 Jun 2025
Viewed by 369
Abstract
Background/Objectives: Sentence stress as part of linguistic prosody plays an important role for verbal communication. It emphasizes particularly important words in a phrase and is reflected by acoustic cues such as the voice fundamental frequency. However, visual cues, especially facial movements, are also [...] Read more.
Background/Objectives: Sentence stress as part of linguistic prosody plays an important role for verbal communication. It emphasizes particularly important words in a phrase and is reflected by acoustic cues such as the voice fundamental frequency. However, visual cues, especially facial movements, are also important for sentence stress perception. Since cochlear implant (CI) recipients are limited in their use of acoustic prosody cues, the question arises as to what extent they are able to exploit visual features. Methods: Virtual characters were used to provide highly realistic but controllable stimuli for investigating sentence stress in groups of experienced CI recipients and typical-hearing (TH) peers. In addition to the proportion of correctly identified stressed words, task load was assessed via reaction times (RTs) and task-evoked pupil dilation (TEPD), and visual attention was estimated via eye tracking. Experiment 1 considered congruent combinations of auditory and visual cues, while Experiment 2 presented incongruent stimuli. Results: In Experiment 1, CI users and TH participants performed similarly in the congruent audiovisual condition, while the former were better at using visual cues. RTs were generally faster in the AV condition, whereas TEPD revealed a more detailed picture, with TH subjects showing greater pupil dilation in the visual condition. The incongruent stimuli in Experiment 2 showed that modality use varied individually among CI recipients, while TH participants relied primarily on auditory cues. Conclusions: Visual cues are generally useful for perceiving sentence stress. As a group, CI users are better at using facial cues than their TH peers. However, CI users show individual differences in the reliability of the various cues. Full article
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34 pages, 5295 KiB  
Article
Candidate Key Proteins of Tinnitus in the Auditory and Motor Systems of the Thalamus
by Johann Gross, Marlies Knipper and Birgit Mazurek
Int. J. Mol. Sci. 2025, 26(12), 5804; https://doi.org/10.3390/ijms26125804 - 17 Jun 2025
Viewed by 632
Abstract
To determine candidate key proteins involved in synaptic transmission in the thalamus in tinnitus, we used bioinformatic methods by analyzing protein–protein interaction networks under different conditions of acoustic activity. The motor system was used to analyze the specificity of the response reaction in [...] Read more.
To determine candidate key proteins involved in synaptic transmission in the thalamus in tinnitus, we used bioinformatic methods by analyzing protein–protein interaction networks under different conditions of acoustic activity. The motor system was used to analyze the specificity of the response reaction in the auditory system. The databases GeneCard, STRING-, DAVID-, and Cytoscape version 3.9.1 were applied to identify the top three high-degree proteins, their high-score interaction proteins and the gene ontology—biological processes (GO-BPs) associated in the thalamus with synaptic transmission in tinnitus. Under normal hearing conditions, a balanced state of functional connectivity was observed for both systems, the auditory system and the motor system of the thalamus. Under conditions of acoustic stimulation, the GO-BP-enrichment analyses suggest that in the auditory system, tinnitus-related proteins may be involved in responses typically associated with “xenobiotic stimuli”; in the motor system, the activation of the dopaminergic system was observed. Under conditions of tinnitus in the auditory system, key proteins and the GO-BPs indicate the regulation of different developmental processes and regulation by microRNA transcription; in the motor system, tinnitus is also identified as “xenobiotic” but responded with GO-BPs, corresponding to various signaling systems, e.g., tachykinin. Key proteins and their interactions with neurotransmitter receptors may be useful indicators for tinnitus-associated changes in synaptic transmission in the thalamic auditory system. Full article
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12 pages, 1391 KiB  
Article
Speech Intelligibility in Virtual Avatars: Comparison Between Audio and Audio–Visual-Driven Facial Animation
by Federico Cioffi, Massimiliano Masullo, Aniello Pascale and Luigi Maffei
Acoustics 2025, 7(2), 30; https://doi.org/10.3390/acoustics7020030 - 23 May 2025
Viewed by 1211
Abstract
Speech intelligibility (SI) is critical in effective communication across various settings, although it is often compromised by adverse acoustic conditions. In noisy environments, visual cues such as lip movements and facial expressions, when congruent with auditory information, can significantly enhance speech perception and [...] Read more.
Speech intelligibility (SI) is critical in effective communication across various settings, although it is often compromised by adverse acoustic conditions. In noisy environments, visual cues such as lip movements and facial expressions, when congruent with auditory information, can significantly enhance speech perception and reduce cognitive effort. In an ever-growing diffusion of virtual environments, communicating through virtual avatars is becoming increasingly prevalent, thus requiring a comprehensive understanding of these dynamics to ensure effective interactions. The present study used Unreal Engine’s MetaHuman technology to compare four methodologies used to create facial animation: MetaHuman Animator (MHA), MetaHuman LiveLink (MHLL), Audio-Driven MetaHuman (ADMH), and Synthetized Audio-Driven MetaHuman (SADMH). Thirty-six word pairs from the Diagnostic Rhyme Test (DRT) were used as input stimuli to create the animations and to compare them in terms of intelligibility. Moreover, to simulate a challenging background noise, the animations were mixed with a babble noise at a signal-to-noise ratio of −13 dB (A). Participants assessed a total of 144 facial animations. Results showed the ADMH condition to be the most intelligible among the methodologies used, probably due to enhanced clarity and consistency in the generated facial animations, while eliminating distractions like micro-expressions and natural variations in human articulation. Full article
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28 pages, 19935 KiB  
Article
Effects of Violin Back Arch Height Variations on Auditory Perception
by Luca Jost, Mehmet Ercan Altinsoy and Hannes Vereecke
Acoustics 2025, 7(2), 27; https://doi.org/10.3390/acoustics7020027 - 14 May 2025
Viewed by 1547
Abstract
One of the quintessential goals of musical instrument acoustics is to improve the perceived sound produced by, e.g., a violin. To achieve this, the connections between physical (mechanical and geometrical) properties and perceived sound output need to be understood. In this article, a [...] Read more.
One of the quintessential goals of musical instrument acoustics is to improve the perceived sound produced by, e.g., a violin. To achieve this, the connections between physical (mechanical and geometrical) properties and perceived sound output need to be understood. In this article, a single facet of this complex problem will be discussed using experimental results obtained for six violins of varying back arch height. This is the first investigation of its kind to focus on back arch height. It may serve to inform instrument makers and researchers alike about the variation in sound that can be achieved by varying this parameter. The test instruments were constructed using state-of-the-art methodology to best represent the theoretical case of changing back arch height on a single instrument. Three values of back arch height (12.1, 14.8 and 17.5 mm) were investigated. The subsequent perceptual tests consisted of a free sorting task in the playing situation and three two-alternative forced choice listening tests. The descriptors “round” and “warm” were found to be linked to back arch height. The trend was non-linear, meaning that both low- and high-arch height instruments were rated as possessing more of these descriptors than their medium-arch height counterparts. Additional results were obtained using stimuli created by hybrid synthesis. However, these could not be linked to those using real playing or recordings. The results of this study serve to inform violin makers about the relative importance of back arch height and its specific influence on sound output. The discussion of the applied methodology and interpretation of results may serve to inform researchers about important new directions in the field of musical instrument acoustics. Full article
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18 pages, 1715 KiB  
Article
Evaluation of the Decrease in DPOAE Levels After VEMP Testing in Clinical Patients Referred to the Vertigo Outpatient Clinic
by Shinnosuke Asakura, Teru Kamogashira, Hideaki Funayama, Toshitaka Kataoka, Shizuka Shoji, Megumi Koizumi, Shinichi Ishimoto and Tatsuya Yamasoba
J. Clin. Med. 2025, 14(8), 2766; https://doi.org/10.3390/jcm14082766 - 17 Apr 2025
Viewed by 436
Abstract
Background/Objectives: The objective of this study is to determine whether the strong acoustic stimuli used in vestibular evoked myogenic potential (VEMP) testing contribute to distortion product otoacoustic emission (DPOAE) level reduction due to noise-induced hearing loss. Methods: The DPOAE levels were [...] Read more.
Background/Objectives: The objective of this study is to determine whether the strong acoustic stimuli used in vestibular evoked myogenic potential (VEMP) testing contribute to distortion product otoacoustic emission (DPOAE) level reduction due to noise-induced hearing loss. Methods: The DPOAE levels were measured routinely to evaluate vestibular balance disorders with sensorineural hearing loss and to monitor changes in cochlear function before and after VEMP. The changes in DPOAE levels after VEMP testing in 174 patients (80 males and 94 females; median age, 53 years [interquartile range, 39–67 years; range, 15–85 years]) who were examined in the vertigo outpatient clinic between June 2021 and December 2024 were retrospectively analyzed. Results: The DPOAE levels decreased significantly after VEMP testing at 1.4 kHz, 2 kHz, 2.8 kHz, sum all 1/2 octave, and average 1/2 octave (1–6 kHz). The decrease in DPOAE levels at 6 kHz exhibited a significant negative linear correlation with age (the coefficient of determination: 0.0189, p = 0.01), but not sex or side. Conclusions: The strong sound stimulation used in VEMP testing can decrease DPOAE levels. The frequencies at which DPOAE levels decreased significantly were overtones of the stimulus frequency, suggesting a possible effect of acoustic stimulation. VEMP testing can be an invasive test method and should be performed with detailed consideration of the risks and benefits. The age factor can influence the decrease in DPOAE levels in VEMP testing. Full article
(This article belongs to the Section Otolaryngology)
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21 pages, 3952 KiB  
Article
Which Factors Enhance the Perceived Restorativeness of Streetscapes: Sound, Vision, or Their Combined Effects? Insights from Four Street Types in Nanjing, China
by Xi Lu, Jiamin Xu, Eckart Lange and Jingwen Cao
Land 2025, 14(4), 757; https://doi.org/10.3390/land14040757 - 1 Apr 2025
Viewed by 697
Abstract
Streetscapes play a critical role in restorative landscapes, offering opportunities for promoting public well-being. Previous studies have predominantly examined the influence of visual and auditory stimuli on perceived restorativeness independently. There is a limited understanding of their interactive effects. In this research, 360 [...] Read more.
Streetscapes play a critical role in restorative landscapes, offering opportunities for promoting public well-being. Previous studies have predominantly examined the influence of visual and auditory stimuli on perceived restorativeness independently. There is a limited understanding of their interactive effects. In this research, 360 participants completed a series of experiments considering four distinct street types, including visual comfort assessment, acoustic environment assessment, and perceived restorativeness. They were assigned to a control group and one of three experimental groups, each receiving specific enhancement: visual stimuli, auditory stimuli, or a combination of audiovisual stimuli. The findings revealed that the experimental groups reported a greater sense of restorativeness compared to the control group. Notably, auditory stimuli demonstrated a more pronounced restorative effect than visual stimuli, while limited differences were found between auditory and audiovisual stimuli. The differences in experimental outcomes among the four street types are compared and discussed, highlighting context-specific guidelines for enhancing streetscape restorativeness. The research findings highlight enhancing the masking effect of soundscape in street environmental design. The study adds a novel multi-sensory approach to the current body of research on restorative landscapes, providing significant insights for the planning and design of streetscapes. Full article
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15 pages, 4456 KiB  
Article
Using Machine Learning for Analysis of Wideband Acoustic Immittance and Assessment of Middle Ear Function in Infants
by Shan Peng, Yukun Zhao, Xinyi Yao, Huilin Yin, Bei Ma, Ke Liu, Gang Li and Yang Cao
Audiol. Res. 2025, 15(2), 35; https://doi.org/10.3390/audiolres15020035 - 31 Mar 2025
Viewed by 743
Abstract
Objectives: Evaluating middle ear function is essential for interpreting screening results and prioritizing diagnostic referrals for infants with hearing impairments. Wideband Acoustic Immittance (WAI) technology offers a comprehensive approach by utilizing sound stimuli across various frequencies, providing a deeper understanding of ear physiology. [...] Read more.
Objectives: Evaluating middle ear function is essential for interpreting screening results and prioritizing diagnostic referrals for infants with hearing impairments. Wideband Acoustic Immittance (WAI) technology offers a comprehensive approach by utilizing sound stimuli across various frequencies, providing a deeper understanding of ear physiology. However, current clinical practices often restrict WAI data analysis to peak information at specific frequencies, limiting its comprehensiveness. Design: In this study, we developed five machine learning models—feedforward neural network, convolutional neural network, kernel density estimation, random forest, and support vector machine—to extract features from wideband acoustic immittance data collected from newborns aged 2–6 months. These models were trained to predict and assess the normalcy of middle ear function in the samples. Results: The integrated machine learning models achieved an average accuracy exceeding 90% in the test set, with various classification performance metrics (accuracy, precision, recall, F1 score, MCC) surpassing 0.8. Furthermore, we developed a program based on ML models with an interactive GUI interface. The software is available for free download. Conclusions: This study showcases the capability to automatically diagnose middle ear function in infants based on WAI data. While not intended for diagnosing specific pathologies, the approach provides valuable insights to guide follow-up testing and clinical decision-making, supporting the early identification and management of auditory conditions in newborns. Full article
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12 pages, 416 KiB  
Article
Comparison of Enriched Acoustic Environment and White Noise as Sound Stimuli for Tinnitus Treatment: A 4-Month Feasibility Study
by Marta Fernández-Ledesma, Ricardo Sanz-Fernández, María Cuesta and Pedro Cobo
Brain Sci. 2025, 15(4), 342; https://doi.org/10.3390/brainsci15040342 - 26 Mar 2025
Viewed by 969
Abstract
Background/Objectives: This study evaluated the feasibility and effectiveness of three sound therapies—enriched acoustic environment with random noise (EAERR), enriched acoustic environment with gamma tones (EAEGT), and white noise (WN)—in alleviating tinnitus distress and enhancing emotional well-being. Methods: A total of 125 [...] Read more.
Background/Objectives: This study evaluated the feasibility and effectiveness of three sound therapies—enriched acoustic environment with random noise (EAERR), enriched acoustic environment with gamma tones (EAEGT), and white noise (WN)—in alleviating tinnitus distress and enhancing emotional well-being. Methods: A total of 125 individuals with tinnitus were recruited, with 92 completing the four-month intervention. Following counseling, participants selected a therapy and listened daily for one hour for four-months at the mixing point intensity. Tinnitus severity and emotional state were assessed at the baseline and post-treatment using the Tinnitus Handicap Inventory (THI), Tinnitus Functional Index (TFI), and Hospital Anxiety and Depression Scale (HADS). Results: All therapies significantly reduced tinnitus distress and improved emotional well-being, with 80.4% of participants reporting benefits. Conclusions: These findings suggest that sound therapies are effective for tinnitus management, though further research with larger and more homogeneous samples is needed to refine their application and optimize treatment for diverse tinnitus profiles. Full article
(This article belongs to the Section Systems Neuroscience)
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20 pages, 2972 KiB  
Review
Intraoperative Monitoring of Sensory Evoked Potentials in Neurosurgery: A Personalized Approach
by Evgeny A. Levin
J. Pers. Med. 2025, 15(1), 26; https://doi.org/10.3390/jpm15010026 - 13 Jan 2025
Viewed by 1842
Abstract
Sensory evoked potentials (EPs), namely, somatosensory, visual, and brainstem acoustic EPs, are used in neurosurgery to monitor the corresponding functions with the aim of preventing iatrogenic neurological complications. Functional deficiency usually precedes structural defect, being initially reversible, and prompt alarms may help surgeons [...] Read more.
Sensory evoked potentials (EPs), namely, somatosensory, visual, and brainstem acoustic EPs, are used in neurosurgery to monitor the corresponding functions with the aim of preventing iatrogenic neurological complications. Functional deficiency usually precedes structural defect, being initially reversible, and prompt alarms may help surgeons achieve this aim. However, sensory EP registration requires presenting multiple stimuli and averaging of responses, which significantly lengthen this procedure. As delays can make intraoperative neuromonitoring (IONM) ineffective, it is important to reduce EP recording time. The possibility of speeding up EP recording relies on differences between IONM and outpatient clinical neurophysiology (CN). Namely, in IONM, the patient is her/his own control, and the neurophysiologist is less constrained by norms and standards than in outpatient CN. Therefore, neurophysiologists can perform a personalized selection of optimal locations of recording electrodes, frequency filter passbands, and stimulation rates. Varying some or all of these parameters, it is often possible to significantly improve the signal-to-noise ratio (SNR) for EPs and accelerate EP recording by up to several times. The aim of this paper is to review how this personalized approach is or may be applied during IONM for recording sensory EPs of each of the abovementioned modalities. Also, the problems hindering the implementation and dissemination of this approach and options for overcoming them are discussed here, as well as possible future developments. Full article
(This article belongs to the Special Issue Personalized Approaches in Neurosurgery)
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14 pages, 1518 KiB  
Article
Tympanic Pre-Operative Electrically Evoked Auditory Late Response (TympEALR) as an Alternative to Trans-Tympanic Tests Using Anesthesia in Cochlear Implant Candidacy
by Daniel Polterauer, Maike Neuling and Florian Simon
J. Clin. Med. 2024, 13(24), 7573; https://doi.org/10.3390/jcm13247573 - 12 Dec 2024
Viewed by 1178
Abstract
Background/Objectives: Before a cochlear implant is considered, patients undergo various audiological tests to assess their suitability. One key test measures the auditory brainstem response (ABR) to acoustic stimuli. However, in some cases, even with maximum sound stimulation, no response is detected. Methods [...] Read more.
Background/Objectives: Before a cochlear implant is considered, patients undergo various audiological tests to assess their suitability. One key test measures the auditory brainstem response (ABR) to acoustic stimuli. However, in some cases, even with maximum sound stimulation, no response is detected. Methods: The promontory test involves electrical stimulation near the auditory nerve, allowing patients to associate the sensation. Ideally, the electrode is placed in the middle ear after opening the eardrum. This method, along with trans-tympanic electrically evoked ABR in local anesthesia (LA-TT-EABR) and the cortical equivalent (LA-TT-EALR), helps assess the auditory nerve’s existence and excitability. The TympEALR test, utilizing a “tympanic LA-TT-EALR”, provides an alternative measurement. Previous research has shown the possibility of deriving brainstem and cortical potentials through trans-tympanic electrical stimulation, allowing for objective assessment of the auditory nerve’s integrity and potentially objectifying patient sensations. Results: Sixteen patients have been tested using TympEALR. In seven of these, we found a positive response. The morphology was similar to other electrically evoked cortical auditory responses (EALR), e.g., using cochlear implants or trans-tympanic stimulation electrodes. We observed a higher influence of electrical artifacts than in other EALRs. Conclusions: TympEALR showed positive results in nearly half of the study participants, potentially avoiding invasive procedures. TympEALR can be a valuable alternative to trans-tympanic methods. More research is needed to determine if a negative result suggests against cochlear implantation. Full article
(This article belongs to the Section Otolaryngology)
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14 pages, 2830 KiB  
Article
Lack of Amino Acid Alterations Within the Cochlear Nucleus and the Auditory Cortex in Acoustic Trauma-Induced Tinnitus Rats Using In Vivo Microdialysis
by Shanshan Yuan, Huey Tieng Tan, Paul F. Smith and Yiwen Zheng
Audiol. Res. 2024, 14(6), 1000-1013; https://doi.org/10.3390/audiolres14060083 - 17 Nov 2024
Viewed by 1286
Abstract
Background/Objectives: Tinnitus is a debilitating auditory disorder commonly described as a ringing in the ears in the absence of an external sound source. Sound trauma is considered a primary cause. Neuronal hyperactivity is one potential mechanism for the genesis of tinnitus and has [...] Read more.
Background/Objectives: Tinnitus is a debilitating auditory disorder commonly described as a ringing in the ears in the absence of an external sound source. Sound trauma is considered a primary cause. Neuronal hyperactivity is one potential mechanism for the genesis of tinnitus and has been identified in the cochlear nucleus (CN) and the auditory cortex (AC), where there may be an imbalance of excitatory and inhibitory neurotransmissions. However, no study has directly correlated tinnitus with the extracellular levels of amino acids in the CN and the AC using microdialysis, which reflects the functions of these neurochemicals. In the present study, rats were exposed to acoustic trauma and then subjected to behavioural confirmation of tinnitus after one month, followed by microdialysis. Methods: Rats were divided into sham (aged, n = 6; young, n = 6); tinnitus-positive (aged, n = 7; young, n = 7); and tinnitus-negative (aged, n = 3; young, n = 3) groups. In vivo microdialysis was utilized to collect samples from the CN and the AC, simultaneously, in the same rat. Extracellular levels of amino acids were quantified using high-performance liquid chromatography (HPLC) coupled with an electrochemical detector (ECD). The effects of sound stimulation and age on neurochemical changes associated with tinnitus were also examined. Results: There were no significant differences in either the basal levels or the sound stimulation-evoked changes of any of the amino acids examined in the CN and the AC between the sham and tinnitus animals. However, the basal levels of serine and threonine exhibited age-related alterations in the AC, and significant differences in threonine and glycine levels were observed in the responses to 4 kHz and 16 kHz stimuli in the CN. Conclusions: These results demonstrate the lack of a direct link between extracellular levels of amino acids in the CN and the AC and tinnitus perception in a rat model of tinnitus. Full article
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16 pages, 3045 KiB  
Article
Application of Sound Waves During the Curing of an Acrylic Resin and Its Composites Based on Short Carbon Fibers and Carbon Nanofibers
by Braian Uribe, Joana Rodrigues, Pedro Costa and Maria C. Paiva
Materials 2024, 17(21), 5369; https://doi.org/10.3390/ma17215369 - 2 Nov 2024
Viewed by 1433
Abstract
Research into particulate polymer composites is of significant interest due to their potential for enhancing material properties, such as strength, thermal stability, and conductivity while maintaining low weight and cost. Among the various techniques for preparing particle-based composites, ultrasonic wave stimulation is one [...] Read more.
Research into particulate polymer composites is of significant interest due to their potential for enhancing material properties, such as strength, thermal stability, and conductivity while maintaining low weight and cost. Among the various techniques for preparing particle-based composites, ultrasonic wave stimulation is one of the principal laboratory-scale methods for enhancing the dispersion of the discontinuous phase. Nevertheless, there is a scarcity of empirical evidence to substantiate the impact of stimulating materials with natural sound frequencies within the acoustic spectrum, ranging from 20 Hz to 20 kHz, during their formation process. The present work investigates the effect of acoustic stimuli with frequencies of 56, 111, and 180 Hz on the properties of an acrylic-based polymer and its discontinuous carbon-based composites. The results indicated that the stimulus frequency affects the cure time of the studied systems, with a notable reduction of 31% and 21% in the cure times of the neat polymer and carbon-nanofiber-based composites, respectively, after applying a frequency of 180 Hz. Additionally, the higher stimulation frequencies reduced porosity in the samples, increased the degree of dispersion of the discontinuous phase, and altered the composite materials’ thermal, optical, and electrical behavior. Full article
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15 pages, 3920 KiB  
Article
Exploring Sound Frequency Detection in the Golden Rabbitfish, Siganus guttatus: A Behavioral Study
by Shenwei Zhang, Xuguang Zhang, Xianming Tang and Shouyu Zhang
Animals 2024, 14(20), 2967; https://doi.org/10.3390/ani14202967 - 14 Oct 2024
Cited by 1 | Viewed by 1068
Abstract
This study investigates the auditory capabilities of Golden Rabbitfish (Siganus guttatus) and the potential efficacy of sound-based deterrent methods for behavior control. Behavioral experiments were conducted on Golden Rabbitfish to assess their responses to sound stimuli. Sinusoidal pulses in the range [...] Read more.
This study investigates the auditory capabilities of Golden Rabbitfish (Siganus guttatus) and the potential efficacy of sound-based deterrent methods for behavior control. Behavioral experiments were conducted on Golden Rabbitfish to assess their responses to sound stimuli. Sinusoidal pulses in the range of 100~800 Hz, based on previous research on auditory evoked potentials (AEPs), were utilized. An analysis of behavioral trajectories, swimming speed, and acceleration changes revealed the fish’s reactions to varying frequency sound stimuli. The results indicate that Golden Rabbitfish exhibited increased swimming activity and speed when stimulated by sound and notably moved away from the source under prolonged exposure to low-frequency acoustic signals. Specifically, the fish displayed the most significant response to 200 Hz sinusoidal pulses with a response threshold of 113~126 dB. These findings suggest that Golden Rabbitfish are particularly sensitive to low-frequency noise, aligning with AEP study outcomes. This study concludes that employing sound stimuli to deter Golden Rabbitfish in practical settings holds promise for mitigating economic losses in seaweed farming due to Golden Rabbitfish grazing. Full article
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