High Frequency Energy Research Articles

Process Parameters of High Frequency Welding.

High frequency (HF) welding of polymer materials is increasingly used in modern manufacturing processes. The literature on HF welding process parameters was reviewed and it was found that 3-5 basic welding parameters were considered, which is insufficient for the scientific study of HF welding of polymeric materials. This article presents the mathematical expressions for the evaluation combining 17 influential parameters. For the first time, the specific and latent heat of the welded polymer material were used. The breaking forces of welds made by RF welding are investigated by varying the anode current, the coupling capacitor, and the exposure time of the HF electromagnetic fields. It was found that the amount of HF energy supplied depends on the breaking forces of the weld. A characteristic inflection point was also observed in the graph of the dependence of the breaking forces on the percentage of the coupling capacitor and the anode current. During elongation, it was observed that the weld is separated by peeling before the inflection point and breaks after the inflection point by tearing at the extruded edges of the weld. If the HF energy is applied to the weld for too long, there will be excessive melting of the material in the weld, thinning of the weld, unfavourable appearance of the extruded edges and electrical breakdown, and a drastic drop in the breaking force.

The optimal Holmium laser settings for disintegration of cystine and calcium oxalate monohydrate stones: In vitro study

ABSTRACT Objective Disintegrating cystine and calcium oxalate monohydrate stones present a formidable challenge owing to their hardness and distinct composition. This study aimed to establish optimal laser settings for these hard stones lithotripsy. Patients and Methods Cystine and calcium oxalate monohydrate stones were extracted from two patients. Two experiments were conducted in vitro by utilizing a 272 μm laser fiber with variable settings to disintegrate the cystine and calcium oxalate monohydrate stones. In the first experiment, energy was adjustable while frequency was constant, whereas the second experiment involved constant energy with adjustable frequency on each type of stone and each experiment was repeated three times to ensure robustness and reliability. Results Our findings indicated that for cystine stones, use of higher total power with high energy and low frequency proved to be effective. Conversely, for calcium oxalate monohydrate stones, settings involving higher total power with low energy and high frequency demonstrated superior efficacy and safety. Conclusion Holmium (Ho: YAG) laser settings with higher total power, high energy, and low frequency effectively disintegrate cystine stones despite increased heat, which was measured by a thermometer with a thermocouple. For calcium oxalate monohydrate stones, higher total power, high frequency, and low energy settings are recommended and safe.

Annoyance penalty due to the spectrum shape of wideband noise

Environmental noise exposure is usually evaluated by measuring the A-weighted equivalent sound pressure level, LAeq [dB]. However, it cannot alone explain the resulting noise annoyance. It is common to apply penalties, such as +5 dB correction, to measured LAeq when the noise contains annoyance accentuating features, such as tonality or impulsiveness. Although previous studies suggest that the noise spectrum also influences annoyance, and spectrum is easy measure, the need of penalty due to spectral shape of noise has not been studied. Our study investigated the relationship between spectral shape and annoyance. The purpose was to determine whether spectrum-related penalties should be integrated with measured LAeq values. We conducted a psychoacoustic laboratory experiment involving 40 participants. We collected their annoyance ratings for 23 spectrally different steady-state wideband noises presented at three LAeq levels, 32, 40, and 48 dB. In addition, annoyance ratings were collected for a spectrally neutral reference noise played within 28–60 dB in 4 dB steps to enable the determination of penalty. The annoyance strongly depended on the spectrum of noise, for all three LAeq levels. Higher concentrations of sound energy in high frequencies were associated with increased annoyance ratings across all three LAeq levels. The penalty values of spectrally modified noises varied within −2 to +12 dB. The penalty values exhibited minimal dependence on LAeq. That is, the same spectrum-related penalties were valid at least within 32–48 dB. Our findings suggest that noise spectrum also deserves a penalty procedure to better explain human perception of noise.

Peculiarities of leakage of the electromagnetic waves from striations

It is well-known that an ordinary (O-mode) high frequency (HF) electromagnetic (EM) wave radiated into the ionosphere generates in the F-region upper-hybrid resonance (UHR) oscillations trapped in small-scale elongated plasma depletions (striations). Striations are not ideal resonators for UHR oscillations. There is some leakage of the HF energy from striations in the form of Z-mode waves. This result obtained in the quasi-electrostatic approximation is partly reconsidered in the present paper. It is shown in the 2D case that two EM waves (instead of one Z-mode) propagate from each side of a striation. The lowest eigenmodes of the electrostatic oscillations trapped in a striation excite at particular heights Z-mode waves that propagate significantly higher than the reflection height of the initial O-mode wave. This result exists for different angles of the O-mode radiation with respect to the vertical (both more and less than the critical angle).

The Acoustic Properties of Affective Timbres: Consistencies and Discrepancies in a Synthesis of Multiple Datasets

In the investigation of musical features that influence musical affect, timbre has received relatively little attention. Investigating affective timbres as they vary between instrument families can lead to inconsistent results, because one instrument family can produce a wide variety of timbres. Here, we consider timbre descriptors, as fine-grained acoustic representations of a sound. Using identical methods, we re-analyzed and synthesized results from three previously published studies: Eerola et al. (2012, Mus. Percept.), McAdams et al. (2017, Front. Psychol.), and Korsmit et al. (2023, Front. Psychol.). In doing so, we aimed to reveal robust timbre descriptors that consistently predict the affective response and to explain any discrepancies in results arising from differences in experimental methodology. We computed spectral, temporal, and spectro-temporal descriptors from all stimuli and used these to predict the affect ratings using linear and nonlinear methods. Our most consistent finding was that the fundamental frequency or higher-frequency energy of a sound predicted pleasant affect (i.e., positive valence, happiness, sadness) in one direction and unpleasant affect (i.e., tension, anger, fear) in the opposite direction. Clear discrepancies in previous findings may be attributable to differences in experimental design. When pitch variation was present in a stimulus set, energy arousal was predicted by pitch and inharmonicity, whereas when attack variation was present in the stimulus set, energy arousal was predicted by a faster attack and shorter sustain.

Analysis of seismic response of a large-scale isolated LNG tank considering dynamic soil-pile interaction

Seismic safety is a critical issue for liquefied natural gas (LNG) tanks. It is essential to investigate the effect of the isolation system on the seismic response of LNG tanks, considering dynamic soil-pile interaction, especially for tanks located in the deep soil site. This study aims to quantitatively evaluate the effects of isolation system (e.g., lead-core rubber bearings) on various aspects of a large LNG tank located on a deep soil site under horizontal bi-directional seismic action. Specifically, the evaluation includes outer tank acceleration, inner tank base shear, overturning moment, and pile force distribution. The findings demonstrate that the isolation system can effectively minimize the transfer of inertial interaction from the superstructure to the pile foundation, optimize the internal force distribution within the pile foundation, mitigate the pile group effect, and enhance the safety margin of the structure. Moreover, the isolation system can effectively suppress the transmission of seismic energy in medium and high frequencies, but amplify it in the low-frequency domain. Consequently, it is recommended that it is needed to avoid the site's natural frequency in the design of seismic isolation bearings for LNG tanks.

Shock wave mitigation and impact resistance response of kevlar fabric with novel shear-stiffening gel core

A novel shear thickening gel with micro-scale hard/soft interface structure and low reaction temperature was proposed in this article. The gel was named TH and used as core material within Kevlar fabrics. Storage modulus of TH was proved to increase by around two orders with increasing of shear frequency, and dynamic properties indicated that TH could dissipate or store more energy. TH can adhere with Kevlar fabrics well and satisfactorily fulfill the gap between fabrics. As a result, shock wave peak pressure and positive impulse decreased markedly. Wavelet decomposition analysis show that high frequency energy was filtered by protection materials. Meanwhile, impact resistance test suggested the existence of TH changed the stress propagation routes and avoided pulling out for Kevlar fabrics. Samples filled with TH demonstrated a better shock wave mitigation ability and impact resistance. Energy dissipation structures with TH have a promising prospect in the application of defending area.

On the Detection of Adaptive Adversarial Attacks in Speaker Verification Systems

Speaker verification systems have been widely used in smart phones and Internet of things devices to identify legitimate users. In recent work, it has been shown that adversarial attacks, such as FAKEBOB, can work effectively against speaker verification systems. The goal of this paper is to design a detector that can distinguish an original audio from an audio contaminated by adversarial attacks. Specifically, our designed detector, called MEH-FEST, calculates the minimum energy in high frequencies from the short-time Fourier transform of an audio and uses it as a detection metric. Through both analysis and experiments, we show that our proposed detector is easy to implement, fast to process an input audio, and effective in determining whether an audio is corrupted by FAKEBOB attacks. The experimental results indicate that the detector is extremely effective: with near zero false positive and false negative rates for detecting FAKEBOB attacks in Gaussian mixture model (GMM) and i-vector speaker verification systems. Moreover, adaptive adversarial attacks against our proposed detector and their countermeasures are discussed and studied, showing the game between attackers and defenders.

Locally Addressable Energy Efficient Actuation of Magnetic Soft Actuator Array Systems.

Advances in magnetoresponsive composites and (electro-)magnetic actuators have led to development of magnetic soft machines (MSMs) as building blocks for small-scale robotic devices. Near-field MSMs offer energy efficiency and compactness by bringing the field source and effectors in close proximity. Current challenges of near-field MSM are limited programmability of effector motion, dimensionality, ability to perform collaborative tasks, and structural flexibility. Herein, a new class of near-field MSMs is demonstrated that combines microscale thickness flexible planar coils with magnetoresponsive polymer effectors. Ultrathin manufacturing and magnetic programming of effectors is used to tailor their response to the nonhomogeneous near-field distribution on the coil surface. The MSMs are demonstrated to lift, tilt, pull, or grasp in close proximity to each other. These ultrathin (80µm) and lightweight (100 gm-2 ) MSMs can operate at high frequency (25 Hz) and low energy consumption (0.5 W), required for the use of MSMs in portableelectronics.

Investigating Spectral Estimates of Stress Drop for Small to Moderate Earthquakes With Heterogeneous Slip Distribution: Examples From the 2016–2017 Amatrice Earthquake Sequence

AbstractEstimates of spectral stress drop are fundamental to understanding the factors controlling earthquake rupture and high frequency ground motion, but are known to include large, poorly‐constrained uncertainties. We use earthquakes from the 2016–2017 sequence in the Italian Appenines (largest event at Norcia, Mw 6.3) to investigate these uncertainties and their causes. The similarly‐sized events near Amatrice (Mw 6.0) and Visso (Mw 5.9) enable better constrained relative analysis. We calculate S wave source spectra, corner frequencies, and spectral stress drop for 30 of the larger events. We compare both empirical and modeling approaches to isolate the source spectra and calculate source parameters; we also compare our results with those from published studies. Both random and systematic inter‐study variations are larger than the standard errors reported by any individual study. The reported magnitude dependence of stress drop varies between studies, being largest for generalized inversions and smallest for more individual event based approaches. The relative spectral estimates of inter‐event stress drop are more consistent; all approaches estimated higher stress drop in the Amatrice earthquake than the similar‐sized Visso earthquake. In contrast, finite fault inversions of these two earthquakes found that the Visso earthquake had the larger region of concentrated, higher slip, whereas the Amatrice earthquake had multiple, lower slip, subevents. The Amatrice spectra contain more high frequency energy than those of the Visso earthquake. This comparison suggests that consistent measurement of a higher spectral stress drop indicates greater high‐frequency ground motion but may correspond to greater rupture complexity rather than higher stress drop.

PD45-06 DUSTING EFFICIENCY FOR THULIUM FIBER LASER: WHEN IT COMES TO FREQUENCY, LESS IS MORE

You have accessJournal of UrologyCME1 Apr 2023PD45-06 DUSTING EFFICIENCY FOR THULIUM FIBER LASER: WHEN IT COMES TO FREQUENCY, LESS IS MORE Francois Soto Palou, Robert Medairos, Junqin Chen, Jodi Antonelli, Michael Lipkin, Glenn Preminger, and Pei Zhong Francois Soto PalouFrancois Soto Palou More articles by this author , Robert MedairosRobert Medairos More articles by this author , Junqin ChenJunqin Chen More articles by this author , Jodi AntonelliJodi Antonelli More articles by this author , Michael LipkinMichael Lipkin More articles by this author , Glenn PremingerGlenn Preminger More articles by this author , and Pei ZhongPei Zhong More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003358.06AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Data from Holmium laser studies has taught us that optimal dusting generally require low energy and high frequency settings. In assessing thulium fiber laser (TFL) technology urologists have often relied on “traditional” dusting settings obtained from Holmium laser trials and experiments. However, these two platforms are fundamentally different in their pulse profile and energy (Ep) delivery. Clinical TFL platforms have an energy range of 0.025J-6J and a frequency (F) range of 1Hz-2400Hz. With the seemingly endless combination of settings and lack of scientific evidence to support one over the other, we aim to provide guidance to the practicing urologists and assess the efficiency of the TFL platform in an automated in vitro “dusting model”. METHODS: All tests were conducted using an IPG Photonics TLR-50W TFL system and a 200μm fiber on “soft” (5:2) Begostone phantoms. We selected the most popular dusting settings (Figure 1) among endourologists familiar with TFL1 and tested each combination of Ep and F settings at four different standoff distances (SD) (0.2mm, 0.5mm 1mm, 2mm) and at clinically significant scanning speeds of 1mm/sec or 2mm/sec, under the same total laser energy delivered to the stone (i.e., 40 J). All pulses were adjusted to maximum peak power and the corresponding pulse duration. The laser fiber was scanned in a 15mm straight line with a 3D positioning system across a polished and submerged Begostone surface. Ablation volumes were quantified by optical coherence tomography (OCT). RESULTS: The maximum stone ablation was achieved at the combination of high energy and low frequency settings (p<0.005). Overall, the settings that produced the greatest ablation volume were 1J/10Hz (2.51mm3) and 1J/20Hz (2.55mm3). For the rectangular pulse profile typically used in TFL, as SD increased ablation volume decreased. CONCLUSIONS: The most efficient dusting settings for dusting using the current TFL occur at high energy, low frequency, and at a short SD of 0.2mm. Further studies are warranted to compare dusting efficiency produced by these settings using human kidney stones. Reference: 1. Sierra A, Corrales M, Piñero A, Traxer O. Thulium fiber laser pre-settings during ureterorenoscopy: Twitter's experts' recommendations. World J Urol. 2022;40(6):1529-1535. doi:10.1007/s00345-022-03966-9 Source of Funding: N/A © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e1164 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Francois Soto Palou More articles by this author Robert Medairos More articles by this author Junqin Chen More articles by this author Jodi Antonelli More articles by this author Michael Lipkin More articles by this author Glenn Preminger More articles by this author Pei Zhong More articles by this author Expand All Advertisement PDF downloadLoading ...

Photothermally induced natural vibration for versatile and high-speed actuation of crystals

The flourishing field of soft robotics requires versatile actuation methodology. Natural vibration is a physical phenomenon that can occur in any material. Here, we report high-speed bending of anisole crystals by natural vibration induced by the photothermal effect. Rod-shaped crystal cantilevers undergo small, fast repetitive bending (~0.2°) due to natural vibration accompanied by large photothermal bending (~1°) under ultraviolet light irradiation. The natural vibration is greatly amplified by resonance upon pulsed light irradiation at the natural frequency to realise high frequency (~700 Hz), large bending (~4°), and high energy conversion efficiency from light to mechanical energy. The natural vibration is induced by the thermal load generated by the temperature gradient in the crystal due to the photothermal effect. The bending behaviour is successfully simulated using finite element analysis. Any light-absorbing crystal can be actuated by photothermally induced natural vibration. This finding of versatile crystal actuation can lead to the development of soft robots with high-speed and high-efficient actuation capabilities.

The soundscape of dense bat swarms: Differences based on location within the group

The laboratory work of Jim Simmons and colleagues has provided key information on how bats use harmonic structure to identify targets from background clutter. Although advantageous for detecting targets straight ahead, the question remains as to how bats modify echolocation, if at all, when identification of objects in the periphery may be needed, such as when flying in a dense group. Based on the work of Dr. Simmons and colleagues, we predicted that free-tailed bats in central positions of swarms may use different echolocation signals than bats on the periphery. We investigated this by quantifying the soundscape based on location within the group. To overcome the challenge of recording inside a dense swarm, we developed a microphone/camera unit carried by a trained Harris hawk that flew through the bat swarm. Frequency spectra were extracted and analyzed based on the frequency-dependent amplitude compared to position in the swarm. We found a significant difference in the soundscape between the ‘Edge’ and ‘Middle’ of the swarm for frequencies above 40 kHz, suggesting bats in central positions of the swarm produce echolocation signals with more energy in higher frequencies, which may aid in distinguishing their calls from conspecifics.

Non‐precious Metal Cu‐Ni Alloy Nanoparticles Supported on Porous Boron Nitride Fibers as Catalysts for Dehydrogenation from Methanolysis of Ammonia‐Borane**

AbstractDehydrogenation from methanolysis of ammonia borane is a promising strategy for the development of sustainable hydrogen energy. Developing an effective and inexpensive catalyst is essential. In our study, a series of Cu−Ni nanoparticles, in the form of alloy, are supported onto porous boron nitride fibers by impregnation reduction. Cu and Ni synergistically interact through the alloys, Cu0.9Ni0.1/p‐BN demonstrates excellent catalytic effect with high turnover frequency (27.1 min−1) and low activation energy (27.8 kJ/mol) at 298 K. Kinetics indicates that the catalyst concentration follows the quasi‐primary reaction. Moreover, the pores of the p‐BN supporter prevent agglomeration of the metal particles while limiting their size, as well as providing protection to the particles. After passing 8 cycles, the catalyst does not suffer from severe poisoning effects. This work greatly enriches the non‐precious metal catalyst system and plays a very meaningful role in the study of dehydrogenation from methanolysis of AB.

Study on the Technology and Mechanism of Cleaning Architectural Aluminum Formwork for Concrete Pouring by High Energy and High Repetition Frequency Pulsed Laser

In the field of construction, the surface of architectural aluminum formwork for concrete pouring will remain the concrete adhesion layer of heterogeneous composite structures. In view of the difficulty of removing the concrete adhesion layer, we studied the technology and mechanism of removing the concrete adhesion layer by laser cleaning technology in this paper. We analyzed the composition and distribution characteristics of residual concrete on the surface of architectural aluminum formwork, set up a laser cleaning test system, carried out laser cleaning experiments on the concrete layer on the surface of architectural aluminum formwork under different storage times, and analyzed the mechanism of removing the concrete adhesion layer by laser cleaning. The experimental results showed that the residual time of concrete will affect the quality and efficiency of laser cleaning concrete residue on the surface of architectural aluminum formwork for concrete pouring. For concrete residues with short residual time, lasering can achieve efficient and high-quality cleaning. A nanosecond pulsed laser could strengthen the surface hardness of the aluminum alloy template during cleaning, which is helpful in improving the durability of the aluminum alloy template. The main mechanisms of laser cleaning to remove the concrete adhesion layer on the surface of architectural aluminum formwork is that the bubbles and water bubbles in the loose structure of concrete instantly absorb high-energy laser and make the concrete aggregate continuously air-burst. This paper provides technological and theoretical support for the application of laser cleaning technology to remove residual concrete on the surface of architectural aluminum formwork for concrete pouring in the field of construction.

The Application of the Dynamic Atmosphere Energy Transport Climate Model (DAET) to Earth’s Semi-Opaque Troposphere

The objective of this work is to apply the Dynamic-Atmosphere Energy Transport (DAET) climate model to a study of the Earth’s semi-opaque troposphere. In this analysis the concept of previous authors has been followed and the Earth’s climate is treated as a single integrated structured system of solar energy collection, thermal energy retention and energy distribution across the Earth’s surface. Unlike previous authors the hemispheric duality of the Earth’s surface is modelled with two separate energy environments of a day lit hemisphere of net energy collection and a dark night surface of net energy loss as fundamental to the design. Using worked examples, it is shown how the Greenhouse Effect results from the summation of two separate physical atmospheric processes, both of which are mathematically equivalent and which together create an energy reservoir within the Earth’s troposphere. These processes are the thermal radiant opacity blocking of radiative physics, and the process of adiabatic convection and conserved energy delivery to far distance of mass-motion physics. Both these processes involve the mathematical infinite summation of halves-of-halves of energy flux and are completely saturated at a surface atmospheric pressure of 1 Bar. It is concluded that the two fundamental controls on terrestrial planetary climate for a given solar system orbit are the downwelling high frequency energy reflection filter of planetary Bond Albedo, and the upwelling low frequency energy bypass to space filter of the Atmospheric Window.

Analysis of preionization effect of excimer laser

Excimer laser plays an important role in the national economic production because of its short wavelength, high repetition frequency and large energy. In the output characteristics of excimer lasers, high beam quality and high energy stability are the characters of high-end excimer light source, and whether the excimer laser system can sufficiently develop the preionization process is the key to output laser pulses with high beam quality and stable energy. This paper is mainly to study the preionization process of ArF excimer laser, and establish one-dimensional simulation calculation model and two-dimensional simulation calculation model. Based on the fluid calculation method of Comsol Multiphysics software, the numerical simulation analysis and calculation are carried out, with the study focusing on the ionization wave propagation process in the preionization process and the relationship between preionization and main discharge. The results show that the spatial structure of corona rod and main electrode should be considered comprehensively when an excimer laser system is designed. Appropriate preionization structure and voltage can make the main discharge triggered during the maintenance of free electrons, which can effectively reduce the discharge voltage, avoid streamer and arc discharge, and improve the output beam quality and system energy stability.

Kilowatt-class high-energy frequency conversion to 95 J at 10 Hz at 515 nm

Abstract We report on frequency doubling of high-energy, high repetition rate ns pulses from a cryogenically gas cooled multi-slab ytterbium-doped yttrium aluminum garnet laser system, Bivoj/DiPOLE, using a type-I phase matched lithium triborate crystal. We achieved conversion to 515 nm with energy of 95 J at repetition rate of 10 Hz and conversion efficiency of 79%. High conversion efficiency was achieved due to successful depolarization compensation of the fundamental input beam.

Gas pressure evolution characteristics of deep true triaxial coal and gas outburst based on acoustic emission monitoring

Coal and gas outburst is one of the geological disasters that seriously threaten the safety of coal mines production. In recent years, with the increase of mining depth, outbursts become frequent. To further explore the occurrence mechanism of deep coal and gas outburst, a self-developed true triaxial coal and gas outburst simulation device was used to simulate the coal and gas outburst at different depths. The results show that with the increase of simulation depth, the critical gas pressure of outburst gradually decreases, and the unit outburst intensity increases sharply. The gas threshold of deep coal and gas outburst is lower. During the incubation and excitation, gas pressure has three special variation rules, namely self-increasing characteristic, stage and instantaneous. In the early incubation, acoustic emission (AE) energy is at a low level, low energy frequency is dominant; in the later incubation, AE energy increases greatly, high energy frequency is dominant. From the perspective of AE energy, a quantitative index that reflects the danger of coal and gas outburst in the incubation is defined, which provides a scientific reference for the prediction and prevention of disasters of coal and gas outburst in deep mining.

Spectral analysis of cough sounds of patients with COVID-19

Cough is a frequent manifestation of COVID-19 (COronaVIrus Disease 2019), therefore, it has an important diagnostic value. There is little information about the characteristics of cough of COVID-19 patients in the literature. To perform a spectral analysis of cough sounds in COVID-19 patients in comparison with induced cough of healthy individuals. Methods. The main group consisted of 218 COVID-19 patients (48.56% – men, 51.44% – women, average age 40.2 (32.4; 50.1) years). The comparison group consisted of 60 healthy individuals (50.0% men, 50.0% women, average age 41.7 (31.2; 53.0) years) who were induced to cough. Each subject had a cough sound recorded, followed by digital processing using a fast Fourier transform algorithm. The temporal-frequency parameters of cough sounds were evaluated: duration (ms), the ratio of the energy of low and medium frequencies (60 – 600 Hz) to the energy of high frequencies (600 – 6 000 Hz), the frequency of the maximum sound energy (Hz). These parameters were determined in relation to both the entire cough and individual phases of the cough sound. Results. Significant differences were found between some cough parameters in the main group and in the comparison group. The total duration of the coughing act was significantly shorter in patients with COVID-19, in contrast to the induced cough of healthy individuals (T = 342.5 (277.0; 394.0) – in the main group; T (c) = 400.5 (359.0; 457.0) – in the comparison group; p = 0.0000). In addition, it was found that the cough sounds of COVID-19 patients are dominated by the energy of higher frequencies as compared to the healthy controls (Q = 0.3095 (0.223; 0.454) – in the main group; Q (c) = 0.4535 (0.3725; 0.619) – in the comparison group; p = 0.0000). The maximum frequency of cough sound energy in the main group was significantly higher than in the comparison group (Fmax = 463.0 (274.0; 761.0) – in the main group; Fmax = 347 (253.0; 488.0) – in the comparison group; p = 0.0013). At the same time, there were no differences between the frequencies of the maximum energy of cough sound of the individual phases of cough act and the duration of the first phase. Conclusion. The cough of patients with COVID-19 is characterized by a shorter duration and a predominance of high-frequency energy compared to the induced cough of healthy individuals.