Acoustic Stimuli Research Articles

Acoustic stimulation during slow wave sleep shows delayed effects on memory performance in older adults

IntroductionIn young healthy adults, phase-locked acoustic stimulation (PLAS) during slow wave sleep (SWS) can boost over-night episodic memory consolidation. In older adults, evidence is scarce and available results are inconsistent, pointing toward reduced PLAS-effectiveness. We argue that multiple stimulation nights are required for effects to unfold in older individuals to compensate for age-related reductions in both SWS and memory performance. We test this assumption in a longitudinal within-subject design.MethodsIn a larger previous project, older adults participated in a three-night intervention receiving either real-PLAS (STIM group) or sham-PLAS (SHAM group). Encoding and immediate recall of face-occupation pairs was administered on the evening of the first intervention night (session one), with feedback-based retrievals ensuing on all following mornings and evenings across the intervention. To test for the benefit of the real-PLAS over sham-PLAS intervention within participants, 16 older adults [agemean: 68.9 (SD: 3.7)] were re-invited receiving the real-PLAS intervention exclusively. This resulted in a SHAMSTIM group (n = 9; T1: sham-PLAS intervention, T2: real-PLAS intervention) and a STIMSTIM group (n = 7; T1 and T2: real-PLAS intervention).ResultsWhile the STIMSTIM group exhibited highly similar responses during T1 and T2, the SHAMSTIM group exhibited a significantly higher increase in memory performance at T2 (real-PLAS) compared to T1 (sham-PLAS). These gains can be attributed to the late stages of the experiment, after three nights of real-PLAS, and remained stable when correcting for changes in baseline sleep quality (PSQI) and baseline cognitive ability (Montreal Cognitive Assessment) between T1 and T2.ConclusionsWe show that in older adults, PLAS-induced memory effects are delayed and manifest over the course of a three-night-PLAS intervention. Our results might explain the lack of effects in previous PLAS studies, where memory performance was solely assessed after a single night of PLAS.

Delving into the significance of the His289Tyr single-nucleotide polymorphism in the glutamate ionotropic receptor kainate-1 (Grik1) gene of a genetically audiogenic seizure model.

Genetic abnormalities affecting glutamate receptors are central to excitatory overload-driven neuronal mechanisms that culminate in seizures, making them pivotal targets in epilepsy research. Increasingly used to advance this field, the genetically audiogenic seizure hamster from Salamanca (GASH/Sal) exhibits generalized seizures triggered by high-intensity acoustic stimulation and harbors significant genetic variants recently identified through whole-exome sequencing. Here, we addressed the influence of the missense single-nucleotide polymorphism (C9586732T, p.His289Tyr) in the glutamate receptor ionotropic kainate-1 (Grik1) gene and its implications for the GASH/Sal seizure susceptibility. Using a protein 3D structure prediction, we showed a potential effect of this sequence variation, located in the amino-terminal domain, on the stability and/or conformation of the kainate receptor subunit-1 protein (GluK1). We further employed a multi-technique approach, encompassing gene expression analysis (RT-qPCR), Western blotting, and immunohistochemistry in bright-field and confocal fluorescence microscopy, to investigate critical seizure-associated brain regions in GASH/Sal animals under seizure-free conditions compared to matched wild-type controls. We detected disruptions in the transcriptional profile of the Grik1 gene within the audiogenic seizure-associated neuronal network. Alterations in GluK1 protein levels were also observed in various brain structures, accompanied by an unexpected lower molecular weight band in the inferior and superior colliculi. This correlated with substantial disparities in GluK1-immunolabeling distribution across multiple brain regions, including the cerebellum, hippocampus, subdivisions of the inferior and superior colliculi, and the prefrontal cortex. Notably, the diffuse immunolabeling accumulated within perikarya, axonal fibers and terminals, exhibiting a prominent concentration in proximity to the cell nucleus. This suggests potential disturbances in the GluK1-trafficking mechanism, which could subsequently affect glutamate synaptic transmission. Overall, our study sheds light on the genetic underpinnings of seizures and underscores the importance of investigating the molecular mechanisms behind synaptic dysfunction in epileptic neural networks, laying a crucial foundation for future research and therapeutic strategies targeting GluK1-containing kainate receptors.

Acoustic Stimulation Appears Promising for Persistent Symptoms of Mild TBI but Requires More Study

Acoustic Stimulation Appears Promising for Persistent Symptoms of Mild TBI but Requires More Study

External stimuli-triggered photodynamic and sonodynamic therapies in combination with hybrid nanomicelles of ICG@PEP@HA: laser vs. ultrasound.

The concept of combining external medical stimuli with internal functional biomaterials to achieve cancer-oriented treatments is being emergingly developed. Optical and acoustical activations have shown particular promise as non-invasive regulation modalities in cancer treatment and intervention. It is always challenging to leverage the contributions of optical and acoustical stimuli and find appropriate biomaterials to optimally match them. Herein, a type of hybrid nanomicelle (ICG@PEP@HA) containing ICG as a photo/sonosensitizer, an amphiphilic peptide for membrane penetration and hyaluronic acid for cluster determinant 44 (CD44) targeting was fabricated. Triggered by the external stimuli of laser and US irradiation, their photo/sonothermal performance, in vitro reactive oxygen species (ROS) production capability and tumor-targeting efficiency have been systematically evaluated. It was interestingly found that the external stimulus of laser irradiation induced a greater quantity of ROS, which resulted in significant cell apoptosis and tumor growth inhibition in the presence of ICG@PEP@HA. The individual analyses and corresponding rationales have been investigated. Meanwhile, these hybrid nanomicelles were administered into MDA-MB-231 tumor-bearing nude mice for PDT and SDT therapies and their biocompatibility assessment, and a prevailing PDT efficacy and reliable bio-safety have been evidenced based on the hematological analysis and histochemical staining. In summary, this study has validated a novel pathway to utilize these hybrid nanomicelles for laser/US-triggered localized tumor treatment, and the treatment efficiency may be leveraged by different external stimuli sources. It is also expected to give rise to full accessibility to clinical translations for human cancer treatments by means of the as-reported laser/US-nanomicelle combination strategy.

Behavioral Assays Dissecting NMDA Receptor Function in Zebrafish.

Zebrafish are a powerful system to study brain development and to dissect the activity of complex circuits. One advantage is that they display complex behaviors, including prey capture, learning, responses to photic and acoustic stimuli, and social interaction (Dreosti et al., Front Neural Circuits 9:39, 2015; Bruckner et al., PLoS Biol 20:e3001838, 2022; Zoodsma et al., Mol Autism 13:38, 2022) that can be probed to assess brain function. Many of these behaviors are easily assayed at early larval stages, offering a noninvasive and high-throughput readout of nervous system function. Additionally, larval zebrafish readily uptake small molecules dissolved in water making them ideal for behavioral-based drug screens. Together, larval zebrafish and their behavioral repertoire offer a means to rapidly dissect brain circuitry and can serve as a template for high-throughput small molecule screens.NMDA receptor subunits are highly conserved in zebrafish compared to mammals (Zoodsma et al., Mol Autism 13:38, 2022; Cox et al., Dev Dyn 234:756-766, 2005; Zoodsma et al., J Neurosci 40:3631-3645, 2020). High amino acid and domain structure homology between humans and zebrafish underlie conserved functional similarities. Here we describe a set of behavioral assays that are useful to study the NMDA receptor activity in brain function.

Exploring acoustic properties of banana fiber composites with elastomeric filler through a computational approach

In recent years, there has been a significant increase in the use of natural fibers as reinforcements in composites. This trend is mainly driven by their eco-friendly nature and wide availability. The objective of this research is to explore the extensive potential of combining Banana Fiber with Tyre Rubber Particles (TRP) as elastomeric fillers in natural fiber composites, focusing primarily on their applications in the automotive and aeronautical industries, particularly in terms of acoustic response. The composite sequences were named as NFC-I to NFC-V, where NFC represented Natural Fiber Composites. To thoroughly investigate the acoustic properties of these innovative composites, experimental analysis on the impedance tube was conducted along with numerical simulations on the Ansys Harmonic Acoustics® module with Transmission Loss (TL) as the key parameter. An orthotropic material model based on the chopped fiber RVE (Representative Volume Element) was developed on the Ansys 2022 R1® Material Designer Module which could be deemed as the novelty of the current work. From the results, it was seen that within the designated frequency bands, specifically the low (67–400 Hz), medium (400–1900 Hz), and high (1900–6300 Hz) ranges, the NFC-4 (15 wt% of TRP) composite consistently demonstrated the lowest average TL values. Conversely, NFC-3 (27 wt% of TRP) consistently showcased the highest TL values, reaching a peak of 27.13 dB in the low-frequency range and 46.73 dB in the high-frequency range. The results obtained from the impedance tube experiments align remarkably well with the numerical simulation outputs, demonstrating the reliability of the numerical model in estimating the transmission loss of composite laminatesa crucial parameter for evaluating acoustic performance.

Quantifying the Impact of Auditory Deafferentation on Speech Perception.

The past decade has seen a wealth of research dedicated to determining which and how morphological changes in the auditory periphery contribute to people experiencing hearing difficulties in noise despite having clinically normal audiometric thresholds in quiet. Evidence from animal studies suggests that cochlear synaptopathy in the inner ear might lead to auditory nerve deafferentation, resulting in impoverished signal transmission to the brain. Here, we quantify the likely perceptual consequences of auditory deafferentation in humans via a physiologically inspired encoding-decoding model. The encoding stage simulates the processing of an acoustic input stimulus (e.g., speech) at the auditory periphery, while the decoding stage is trained to optimally regenerate the input stimulus from the simulated auditory nerve firing data. This allowed us to quantify the effect of different degrees of auditory deafferentation by measuring the extent to which the decoded signal supported the identification of speech in quiet and in noise. In a series of experiments, speech perception thresholds in quiet and in noise increased (worsened) significantly as a function of the degree of auditory deafferentation for modeled deafferentation greater than 90%. Importantly, this effect was significantly stronger in a noisy than in a quiet background. The encoding-decoding model thus captured the hallmark symptom of degraded speech perception in noise together with normal speech perception in quiet. As such, the model might function as a quantitative guide to evaluating the degree of auditory deafferentation in human listeners.

Neural coordination of bilateral hand movements: evidence for an involvement of brainstem motor centres.

Bilateral hand movements are assumed to be coordinated by a neural coupling mechanism. Neural coupling is experimentally reflected in complex electromyographic (EMG) responses in the forearm muscles of both sides to unilateral electrical arm nerve stimulation (ES). The aim of this study was to examine a potential involvement of the reticulospinal system in neural coupling by the application of loud acoustic stimuli (LAS) known to activate neurons of this system. LAS, ES and combined LAS/ES were applied to healthy subjects during visually guided bilateral hand flexion-extension movements. Muscle responses to the different stimuli were evaluated by electrophysiological recordings. Unilateral electrical ulnar nerve stimulation resulted in neural coupling responses in the forearm extensors (FE) of both sides. Interestingly, LAS evoked bilateral EMG responses that were similar in their configuration to those induced by ES. The presence of startles was associated with a shift of the onset and enhanced amplitude of LAS-induced coupling-like responses. Upon combined LAS/ES application, ES facilitated ipsilateral startles and coupling-like responses. Modulation of coupling-like responses by startles, the similarity of the responses to ES and LAS, and their interaction following combined stimulation suggests that both responses are mediated by the reticulospinal system. Our findings provide novel indirect evidence that the reticulospinal system is involved in the neural coupling of hand movements. This becomes clinically relevant in subjects with a damaged corticospinal system where a dominant reticulospinal system leads to involuntary limb coupling, referred to as associated movements. KEY POINTS: Automatic coordination of hand movements is assumed to be mediated by a neural coupling mechanism reflected by bilateral reflex responses in forearm muscles to unilateral electrical arm nerve stimulation (ES). Loud acoustic stimuli (LAS) were applied to assess a potential involvement of the reticulospinal system in the neural coupling mechanism. LAS evoked a bilateral reflex response in the forearm extensors that was similar to the neural coupling response to ES, and which could be separated from the acoustic startle response. Combined application of LAS and ES resulted in a facilitation of startle and coupling-like responses ipsilateral to ES, thus indicating an interaction of afferences from both stimuli. These novel findings provide indirect evidence that the reticulospinal system is a key motor structure for the coupling of bilateral hand movements.

Using a standardized sound set to help characterize misophonia: The International Affective Digitized Sounds.

Misophonia is a condition characterized by negative affect, intolerance, and functional impairment in response to particular repetitive sounds usually made by others (e.g., chewing, sniffing, pen tapping) and associated stimuli. To date, researchers have largely studied misophonia using self-report measures. As the field is quickly expanding, assessment approaches need to advance to include more objective measures capable of differentiating those with and without misophonia. Although several studies have used sounds as experimental stimuli, few have used standardized stimuli sets with demonstrated reliability or validity. To conduct rigorous research in an effort to better understand misophonia, it is important to have an easily accessible, standardized set of acoustic stimuli for use across studies. Accordingly, in the present study, the International Affective Digitized Sounds (IADS-2), developed by Bradley and Lang (Bradley MM et al., 2007), were used to determine whether participants with misophonia responded to certain standardized sounds differently than a control group. Participants were 377 adults (132 participants with misophonia and 245 controls) recruited from an online platform to complete several questionnaires and respond to four probes (arousal, valence, similarity to personally-relevant aversive sounds, and sound avoidance) in response to normed pleasant, unpleasant, and neutral IADS-2 sounds. Findings indicated that compared to controls, participants with high misophonia symptoms rated pleasant and neutral sounds as significantly more (a) arousing and similar to trigger sounds in their everyday life, (b) unpleasant and (c) likely to be avoided in everyday life. For future scientific and clinical innovation, we include a ranked list of IADS-2 stimuli differentiating responses in those with and without misophonia, which we call the IADS-M.

Electrically evoked late latency response using single electrode stimulation and its relation to speech perception among paediatric cochlear implant users.

Aided auditory late latency response (LLR) serves as an objective tool for evaluating auditory cortical maturation following cochlear implantation in children. While aided LLR is commonly measured using sound-field acoustic stimulation, recording electrically evoked LLR (eLLR) offer distinct advantages, such as improved stimulus control and the capability for single electrode stimulation. Hence, the study aimed to compare eLLR responses with single electrode stimulation in the apical, middle, and basal regions and to evaluate their relationship with speech perception in paediatric cochlear implant (CI) recipients. eLLR responses with single electrode stimulation were measured in 27 paediatric unilateral CI users with an active recording electrode placed at Cz. The stimuli consisted of 36 msec biphasic pulse trains presented across three electrode sites (apical-E20, middle-E11, and basal-E03). eLLR responses were compared across these electrode sites, and the relationship between speech recognition scores in quiet and age at implantation with eLLR components was evaluated. eLLR responses were detected in 77 out of 81 tested electrodes of all participants combined (27 for apical, 26 for middle, and 24 for basal stimulation). There were no significant differences in P1, N1 latencies and P1 amplitude across electrode site. However, significantly larger N1 and P1-N1 amplitudes were observed for apical stimulations compared to basal stimulations. No differences in N1 amplitude were found between middle and apical stimulations, and the P1-N1 amplitude was significantly larger for middle compared to basal electrode stimulation, with no difference between the apical and middle electrodes stimulation. A moderate positive correlation was present between speech recognition scores in quiet and both N1, P1-N1 amplitudes for apical stimulation. Age at implantation was negatively correlated with N1 amplitude for the apical and P1-N1 amplitude for basal stimulation. eLLR responses could be elicited in majority of paediatric CI users across electrode sites. Variations in eLLR responses across electrode sites suggest disparities in auditory cortical maturation. The findings underscore the significance of the N1 biomarker in evaluating higher-order auditory cortical development. Therefore, utilizing eLLR with single electrode stimulation may serve as a valuable tool for assessing post-cochlear implantation maturational changes in paediatric populations.

Stimulative piezoelectric nanofibrous scaffolds for enhanced small extracellular vesicle production in 3D cultures.

Small extracellular vesicles (sEVs) have great promise as effective carriers for drug delivery. However, the challenges associated with the efficient production of sEVs hinder their clinical applications. Herein, we report a stimulative 3D culture platform for enhanced sEV production. The proposed platform consists of a piezoelectric nanofibrous scaffold (PES) coupled with acoustic stimulation to enhance sEV production of cells in a 3D biomimetic microenvironment. Combining cell stimulation with a 3D culture platform in this stimulative PES enables a 15.7-fold increase in the production rate per cell with minimal deviations in particle size and protein composition compared with standard 2D cultures. We find that the enhanced sEV production is attributable to the activation and upregulation of crucial sEV production steps through the synergistic effect of stimulation and the 3D microenvironment. Moreover, changes in cell morphology lead to cytoskeleton redistribution through cell-matrix interactions in the 3D cultures. This in turn facilitates intracellular EV trafficking, which impacts the production rate. Overall, our work provides a promising 3D cell culture platform based on piezoelectric biomaterials for enhanced sEV production. This platform is expected to accelerate the potential use of sEVs for drug delivery and broad biomedical applications.

In vivo high-speed microscopy of microbubbles in the chorioallantoic membrane model.

Rationale: The acoustic stimulation of microbubbles within microvessels can elicit a spectrum of therapeutically relevant bioeffects from permeabilization to perfusion shutdown. These bioeffects ultimately arise from complex interactions between microbubbles and microvascular walls, though such interactions are poorly understood particularly at high pressure, due to a paucity of direct in vivo observations. The continued development of focused ultrasound methods hinges in large part on establishing links between microbubble-microvessel interactions, cavitation signals, and bioeffects. Methods: Here, a system was developed to enable simultaneous high-speed intravital imaging and cavitation monitoring of microbubbles in vivo in a chorioallantoic membrane model. Exposures were conducted using the clinical agent DefinityTM under conditions previously associated with microvascular damage (1 MHz, 0.5-3.5 MPa, 5 ms pulse length). Results: Ultrasound-activated microbubbles could be observed and were found to induce localized wall deformations that were more pronounced in smaller microvessels and increased with pressure. A central finding was that microbubbles could extravasate from microvessels (from 34% of vessels at 1 MPa to 79% at 3 MPa) during insonation (94% within 0.5 ms) and that this occurred more frequently and in progressively larger microvessels (up to 180 µm) as pressure was increased. Following microbubble extravasation, transient or sustained red blood cell leakage ensued at the extravasation site in 96% of cases for pressures ≥1 MPa. Conclusions: The results here represent the first high-speed in vivo investigation of high-pressure focused ultrasound-induced microbubble-microvessel interactions. This data provides direct evidence that the process of activated microbubble extravasation can occur in vivo and that it is linked to producing microvessel wall perforations of sufficient size to permit red blood cell leakage. The association of red blood cell leakage with microbubble extravasation provides mechanistic insight into the process of microvessel rupture, which has been widely observed in histology.

Futuristic Alzheimer's therapy: acoustic-stimulated piezoelectric nanospheres for amyloid reduction.

The degeneration of neurons due to the accumulation of misfolded amyloid aggregates in the central nervous system (CNS) is a fundamental neuropathology of Alzheimer's disease (AD). It is believed that dislodging/clearing these amyloid aggregates from the neuronal tissues could lead to a potential cure for AD. In the present work, we explored biocompatible polydopamine-coated piezoelectric polyvinylidene fluoride (DPVDF) nanospheres as acoustic stimulus-triggered anti-fibrillating and anti-amyloid agents. The nanospheres were tested against two model amyloidogenic peptides, including the reductionist model-based amyloidogenic dipeptide, diphenylalanine, and the amyloid polypeptide, amyloid beta (Aβ42). Our results revealed that DPVDF nanospheres could effectively disassemble the model peptide-derived amyloid fibrils under suitable acoustic stimulation. In vitro studies also showed that the stimulus activated DPVDF nanospheres could efficiently alleviate the neurotoxicity of FF fibrils as exemplified in neuroblastoma, SHSY5Y, cells. Studies carried out in animal models further validated that the nanospheres could dislodge amyloid aggregates in vivo and also help the animals regain their cognitive behavior. Thus, these acoustic stimuli-activated nanospheres could serve as a novel class of disease-modifying nanomaterials for non-invasive electro-chemotherapy of Alzheimer's disease.

A Flower Pollination Algorithm-Optimized Wavelet Transform and Deep CNN for Analyzing Binaural Beats and Anxiety

Binaural beats are a low-frequency form of acoustic stimulation that may be heard between 200 and 900 Hz and can help reduce anxiety as well as alter other psychological situations and states by affecting mood and cognitive function. However, prior research has only looked at the impact of binaural beats on state and trait anxiety using the STA-I scale; the level of anxiety has not yet been evaluated, and for the removal of artifacts the improper selection of wavelet parameters reduced the original signal energy. Hence, in this research, the level of anxiety when hearing binaural beats has been analyzed using a novel optimized wavelet transform in which optimized wavelet parameters are extracted from the EEG signal using the flower pollination algorithm, whereby artifacts are removed effectively from the EEG signal. Thus, EEG signals have five types of brainwaves in the existing models, which have not been analyzed optimally for brainwaves other than delta waves nor has the level of anxiety yet been analyzed using binaural beats. To overcome this, deep convolutional neural network (CNN)-based signal processing has been proposed. In this, deep features are extracted from optimized EEG signal parameters, which are precisely selected and adjusted to their most efficient values using the flower pollination algorithm, ensuring minimal signal energy reduction and artifact removal to maintain the integrity of the original EEG signal during analysis. These features provide the accurate classification of various levels of anxiety, which provides more accurate results for the effects of binaural beats on anxiety from brainwaves. Finally, the proposed model is implemented in the Python platform, and the obtained results demonstrate its efficacy. The proposed optimized wavelet transform using deep CNN-based signal processing outperforms existing techniques such as KNN, SVM, LDA, and Narrow-ANN, with a high accuracy of 0.99%, precision of 0.99%, recall of 0.99%, F1-score of 0.99%, specificity of 0.999%, and error rate of 0.01%. Thus, the optimized wavelet transform with a deep CNN can perform an effective decomposition of EEG data and extract deep features related to anxiety to analyze the effect of binaural beats on anxiety levels.

Interactions Between Slopes of Residual Hearing and Frequency Maps in Simulated Bimodal and Electric-Acoustic Stimulation Hearing.

The aim of this study was to determine the effects of residual hearing slopes and cochlear implant frequency map settings on bimodal and electric-acoustic stimulation (EAS) benefits in speech perception. Adults with normal hearing were recruited for simulated bimodal and EAS hearing. Sentence perception was measured unilaterally and bilaterally. For the acoustic stimulation, three slopes of high-frequency hearing loss were created using low-pass filters with a cutoff frequency of 500 Hz: steep (96 dB/octave), medium (48 dB/octave), and shallow (24 dB/octave). For the electric stimulation, an eight-channel sinewave vocoder was used with an output frequency range (1000-7938 Hz) with three input frequency ranges to create frequency maps, overlap (188-7938 Hz), meet (500-7938 Hz), and gap (750-7938 Hz), relative to the cutoff frequency in the acoustic stimulation. The largest bimodal/EAS benefit occurred with the shallow slope, and the smallest occurred with the steep slope. The effects of the slopes on bimodal/EAS benefit were greatest with the meet or gap map and the least with the overlap map. EAS benefit was greater than bimodal benefit at higher signal-to-noise ratios regardless of frequency map. The results indicate that correlation between bimodal/EAS benefit and residual hearing could potentially improve if slopes were considered. The optimal frequency map differed with different slopes, suggesting that the slopes of residual hearing should be carefully considered in fitting bimodal and EAS hearing. EAS hearing provided greater benefit over bimodal hearing, suggesting that spectrotemporal integration was better within one ear (i.e., EAS) than across ears (i.e., bimodal).

Sound management strategies in swiftlet ranching from Southern Thailand

Abstract. Pongpattananurak N, Phumsathan S, Somleewong T, Rasri P. 2023. Sound management strategies in swiftlet ranching: An experiment from Southern Thailand. Biodiversitas 24: 6218-6228. Edible-nest swiftlets are well-known for the medicinal properties of their nests. With the global demand, swiftlet ranching has emerged as a vital industry. Swiftlet houses employ acoustic stimuli to entice wild swiftlets. However, the use of loud acoustic stimuli in swiftlet houses has inadvertently led to sound pollution in urban areas. This study investigates the interplay of acoustic stimuli, loudness, and environmental factors in attracting swiftlets while reducing noise. Our findings highlight the critical role of sound management in swiftlet ranching. Higher loudness, especially around 80-90 dB, significantly increases swiftlet activity and maximizes daily counts. Furthermore, optimizing loudness levels, particularly at around 80 dB, extends the swiftlet presence duration, offering valuable ranching benefits. Strategic loudness management is recommended to balance attraction and noise control. Timing acoustic stimulation during mornings and late afternoons aligns with swiftlets' natural behavior. Lowering loudness to under 70 dB during midday minimizes disturbances, especially in populated areas. Weather conditions, including outdoor absolute humidity and temperature, also influence swiftlet attraction. The study finally provides guidance for complying with environmental noise regulations, demonstrating that sound levels of 70-80 dB effectively control noise. These insights support swiftlet ranching while respecting urban communities and coexisting harmoniously.

Behavioral observations, heart rate and heart rate variability in horses following oral administration of a cannabidiol containing paste in three escalating doses (part 1/2).

Cannabidiol (CBD) products have been proposed to exert stress- and anxiety-relieving effects in animals. Despite the increasing popularity of CBD for veterinary use, the available research detailing the effects of CBD in horses is limited. The aim of this study (part 1 of 2) was to analyze stress parameters via behavioral observations and heart rate monitoring in healthy horses following single oral administration of a CBD containing paste in different doses. Study products were two pastes for oral administration, one containing CBD and one containing no active ingredient. Pastes were applied as single administrations in consecutive trials with escalating dosages (doses: 0.2, 1.0, 3.0 mg CBD/kg) to a treatment (trial 1: n = 3, trial 2: n = 3, trial 3: n = 5 horses) and a control group (trial 1: n = 3, trial 2: n = 3, trial 3: n = 6 horses) with minimum wash-out periods of seven days in between. Behavioral parameters were evaluated using video recordings to score the levels of sedation including the horses' reactions to acoustic and visual stimuli. Facial expression was assessed using photographs. Evaluation was based on the previously described facial sedation scale for horses (FaceSed) and the Horse Grimace Scale. For baseline values, identical observations were recorded on the day before each paste administration. Both paste administration and behavioral evaluation were performed double blinded. Cardiac beat-to-beat (R-R) intervals were continuously recorded throughout the trial and assessed using heart rate and heart rate variability parameters. Statistical analysis included comparison between treatment and control group over escalating doses and time points using linear mixed models. The CBD paste was well tolerated, and no side effects were observed. Analysis of sedation scores and facial expressions did not indicate significant differences between treatment and control group over the escalating doses. The heart rate was neither reduced, nor were significant changes in heart rate variability observed compared to the control group. Main limitation of this study is the small sample size. Further research is required to determine adequate doses and indications for the use of CBD products in horses.

Short-term observation of electrical acoustic stimulation in patients with low frequency residual hearing after cochlear implant

Objective: To analyze the effects of electrical acoustic stimulation (EAS) on speech and tone recognition as well as music perception in children with low-frequency residual hearing (LFRH) after cochlear implant (CI). Methods: A total of twelve Mandarin patients with LFRH who underwent unilateral CI from January 2017 to October 2020 were recruited, including 8 males and 4 females. There were 5 cases of pre-lingual deafness and 7 cases of post-lingual deafness. The median age at implantation was 12 years old (3-62 years). All patients had residual hearing (RH) before surgery, wore hearing aid (HA) timely, had an effective rehabilitation and the duration of use of electrical stimulation was 37.0±16.2 months. On the implanted side, the thresholds of 125 Hz and 250 Hz were less than and equal to 80 dB HL after implantation. A two-month follow-up clinical study was conducted with the EAS devices. The EAS effects were evaluated before, immediately after and 2 months after upgrade, including speech recognition rate, tone recognition and music tests. SPSS 23.0 software was used for statistical analysis. Results: A total of ten patients completed a two-month clinical follow-up and efficiency evaluation. Compared to the electrical stimulation, the recognition rate of spondee word significantly decreased after the immediate use of EAS (71.7±4.3 vs 79.6±3.1, P=0.018). Compared to the electrical stimulation as well as immediate use of EAS, the results of sentence in noise, tone in noise, and SRT of sentence in noise were all significantly improved at 2 months after use of EAS (P<0.05). The pitch discrimination was significantly improved at 2 months after the use of EAS compared with that before the use of EAS (P=0.042). Compared with before (P=0.021) and immediately (P=0.017) use of EAS, the ability of rhythm resolution was significantly improved. There were no significant differences in other test results (P>0.05). Conclusions: The low-frequency acoustic information provided by EAS as well as the electrical-acoustic stimulation mode can provide rich auditory cues of speech perception in noise, tone recognition in noise, and musical discrimination for CI subjects. It can promote the improvement of complex listening ability of CI patients undergoing long-term electrical stimulation in a short time and comprehensively improve their hearing capacities.

Acoustic stimulation for relieving pain during venipuncture: a systematic review and network meta-analysis

ObjectivesTo assess whether acoustic stimulations relieve venipuncture pain and determine which stimulation is the most effective type.DesignSystematic review and network meta-analysis.Data sourcesPubMed, Cochrane Central Register of Controlled Trials, Excerpta Medica...

Acoustic stimulation during sleep predicts long-lasting increases in memory performance and beneficial amyloid response in older adults.

Sleep and neurodegeneration are assumed to be locked in a bi-directional vicious cycle. Improving sleep could break this cycle and help to prevent neurodegeneration. We tested multi-night phase-locked acoustic stimulation (PLAS) during slow wave sleep (SWS) as a non-invasive method to improve SWS, memory performance and plasma amyloid levels. 32 healthy older adults (agemean: 68.9) completed a between-subject sham-controlled three-night intervention, preceded by a sham-PLAS baseline night. PLAS induced increases in sleep-associated spectral-power bands as well as a 24% increase in slow wave-coupled spindles, known to support memory consolidation. There was no significant group-difference in memory performance or amyloid-beta between the intervention and control group. However, the magnitude of PLAS-induced physiological responses were associated with memory performance up to 3 months post intervention and beneficial changes in plasma amyloid. Results were exclusive to the intervention group. Multi-night PLAS is associated with long-lasting benefits in memory and metabolite clearance in older adults, rendering PLAS a promising tool to build upon and develop long-term protocols for the prevention of cognitive decline.