Soundwaves

Bubbles oscillating in the presence of ultrasound is commonly employed in biomedical applications for drug delivery, ultrasound enhanced thrombolysis, and the transport and manipulation of cells. This is possible because bubbles tend to interact with the ultrasound to undergo periodic shape changes known as shape-mode oscillation, concomitant with the generation of liquid agitation or streaming. This phenomenon is examined both experimentally and theoretically on a single bubble at a frequency of (45 ± 1) kHz...

Understanding biological systems in terms of scientific materialism has arguably reached a frontier, leaving fundamental questions about their complexity unanswered. In 1998, Friedrich Cramer proposed a general resonance theory as a way forward. His theory builds on the extension of the quantum physical duality of matter and wave to the macroscopic world. According to Cramer' theory, agents constituting biological systems oscillate, akin to musical soundwaves, at specific eigenfrequencies. Biological system dynamics can be described as "Symphonies of Life" emerging from the resonance (and dissonance) of eigenfrequencies within the interacting collective...

The majority of reported measurements on high intensity ultrasound beams in air are below 40 kHz and performed on standing waves inside of a guide. Here, experimental characterization of high intensity progressive and divergent sound beams in air at 300 kHz are presented. Measurements in this frequency range are challenging. Accurate characterization of high intensity sound beams requires a measurement bandwidth at least ten times the beam's primary frequency, as high intensity soundwaves steepen and form shocks and, therefore, contain significant signal power at harmonic frequencies...

INTRODUCTION: The spread of antimicrobial resistance (AMR) is a major threat to human and animal health. Therefore, new solutions are needed to prevent returning to a world without effective antibiotics. Mastitis in dairy cows is a major reason for antimicrobial use in food animal production, and mastitis-causing bacteria have the potential to develop AMR. In this study, acoustic pulse technology (APT) was explored as an alternative to antimicrobials for the treatment of mastitis in dairy cows...

Understanding speech requires mapping fleeting and often ambiguous soundwaves to meaning. While humans are known to exploit their capacity to contextualize to facilitate this process, how internal knowledge is deployed online remains an open question. Here, we present a model that extracts multiple levels of information from continuous speech online. The model applies linguistic and nonlinguistic knowledge to speech processing, by periodically generating top-down predictions and incorporating bottom-up incoming evidence in a nested temporal hierarchy...

The manipulation of refracted wavefronts is eye-catching for owning attractive applications. In this article, an airborne acoustic flat lens for broadband focusing via cross-shape structure was proposed and demonstrated, introducing the broadband manipulation of wavefronts. The designed metasurface employs gradient refractive index cells to redirect the sound wave. Based on our theory, the effective refractive indexes of our unit cells can be easily calculated. The shackle of narrowband metasurfaces is conquered, and applications in medical ultrasound imaging are just around the corner...

Similar to ultrasound adapting soundwaves to depict the inner structures and tissues, optical coherence tomography (OCT) utilizes low coherence light waves to assess characteristics in the eye. Compared to the previous gold standard diagnostic imaging fluorescein angiography, OCT is a noninvasive imaging modality that generates images of ocular tissues at a rapid speed. Two commonly used iterations of OCT include spectral-domain (SD) and swept-source (SS). Each comes with different wavelengths and tissue penetration capacities...

Sound waves are all around us resonating at audible and inaudible frequencies. Our ability to hear is crucial in providing information and enabling interaction with our environment. The human brain generates neural oscillations or brainwaves through synchronised electrical impulses. In epilepsy these brainwaves can change and form rhythmic bursts of abnormal activity outwardly appearing as seizures. When two waveforms meet, they can superimpose onto one another forming constructive, destructive or mixed interference...

Acoustics recordings from laser-induced plasmas are becoming increasingly regarded as a complementary source of information from the inspected sample. The propagation of these waves is susceptible to be modified by the physicochemical traits of the sample, thus yielding specific details that can be used for sorting and identification of targets. Still, the relative fragility of the acoustic wave poses major challenges to the applicability of laser-induced acoustics. Echoes and reflections sourcing from intrasample parameters as well as from interactions of the acoustic wave with the surroundings of the inspected target can dilute the analytical information directly related to the object contained within the recordings...

Wearing masks has been a recommended protective measure due to the risks of coronavirus disease 2019 (COVID-19) even in its coming endemic phase. Therefore, deploying a "smart mask" to monitor human physiological signals is highly beneficial for personal and public health. This work presents a smart mask integrating an ultrathin nanocomposite sponge structure-based soundwave sensor (≈400 µm), which allows the high sensitivity in a wide-bandwidth dynamic pressure range, i.e., capable of detecting various respiratory sounds of breathing, speaking, and coughing...

The tumor microenvironment (TME), consisting of extracellular matrix, proteins, stromal cells, and a vascular system, is reported to have a key role in cancer progression and prognosis. Thereby, the interaction between the vascular network and tumor mass is an important feature of the TME since the anticancer agents which are delivered to the TME can trigger the vascular response and influence the therapeutic outcome of the treatment. To identify and develop new therapeutic strategies, 3D in vitro models that recapitulate the complexity of the TME are urgently needed...

Sound is a complex feature of all environments, but captive animals' soundscapes (acoustic scenes) have been studied far less than those of wild animals. Furthermore, research across farms, laboratories, pet shelters, and zoos tends to focus on just one aspect of environmental sound measurement: its pressure level or intensity (in decibels). We review the state of the art of captive animal acoustic research and contrast this to the wild, highlighting new opportunities for the former to learn from the latter...

OBJECTIVES: Ultrasound measurements of muscle echo intensity are commonly used surrogates of muscle composition (eg, intramuscular adipose tissue). However, given that soundwaves are increasingly attenuated with tissue depth, the interpretation of echo intensity may be confounded by adipose and skeletal muscle thickness. Our objectives are to compare the associations between adipose or muscle tissue thickness and rectus femoris echo intensity in younger and older males and females. METHODS: Participants included in this analysis were derived from 3 previously published cohorts of younger (<45 years) and older (≥60 years) males and females...

In a reverberant environment, humans with normal hearing can perceptually fuse the soundwave from a source with its reflections off nearby surfaces into a single auditory image, whose location appears to be around the source. This phenomenon is called the precedence effect, which is based on the perceptual capture of the reflected (lagging) sounds' attributes by the direct wave from the source. Using the paradigm of attentional modulation of the prepulse inhibition (PPI) of the startle reflex, with both the prepulse-feature specificity and the perceived-prepulse-location specificity, this study was to examine whether the perceptual attribute capture underlying the precedence effect occurs in rats...

A soundwave is transmitted by adjacent molecules in the medium, and depending on the type of sound, it exhibits various characteristics such as frequency, sound pressure, etc. If the acoustic wavelength of the soundwave is sufficiently long compared with the size of an acoustic element, physical analysis within the sound element could be simplified regardless of the shape of the acoustic element: this is called "long wavelength approximation". A Helmholtz resonator, a representative acoustic element which satisfies the "long wavelength theory", consists of a neck part and a cavity part...

A link is established between biomechanical and acoustic 3D models for the numerical simulation of vowel-vowel utterances. The former rely on the activation and contraction of relevant muscles for voice production, which displace and distort speech organs. However, biomechanical models do not provide a closed computational domain of the 3D vocal tract airway where to simulate sound wave propagation. An algorithm is thus proposed to extract the vocal tract boundary from the surrounding anatomical structures at each time step of the transition between vowels...

A molecular dynamics (MD) simulation was performed to study the propagation of soundwaves in a fluid. Soundwaves are generated by a sinusoidally oscillating wall and annihilated by a locally applied Langevin thermostat near the opposite wall. The waveform changes from sinusoidal to sawtooth with increasing wave amplitude. For low-frequency sounds, the simulation results show a very good agreement with Burgers's equation without any fitting parameters. In contrast, for high-frequency sounds, significant deviations are obtained because of acoustic streaming...

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PURPOSE: To correlate the subjective quality assessment of ear canal acoustics of the participants to the objective measurement of the ear canal acoustics. The objective ear canal acoustics is the frequency-dependent modulation of soundwaves through the ear canal. Our second objective is to design a model to predict the subjective quality of sound based on the altered objective ear canal acoustics. METHODS: To determine the frequency-dependent modulation of the soundwaves the real-ear unaided gain (REUG) of the ear canal is measured...

Apart from Von Békésy's traveling wave theory, this paper introduces our new comprehension on auditory system based on acoustic resonance in hair cells. Focusing on a rootlet inductance L and a membrane capacitance C of the hair cell, a real-sized cell model is designed so as to form a series LC resonant circuit for the incident soundwaves. In simulation, acoustic resonance is observed successfully at 1120 Hz together with 148-times sound pressure enhancement inside the cell. This model is useful to explain OAE responses, frequency shifts of absolute pitch for aging, pure-tone tinnitus, and even apoptosis of outer hair cells by huge sound exposure...