Middle Frequencies Research Articles

Clinical features of hearing loss caused by STRC gene deletions/mutations in Russian population

Congenital sensorineural hearing loss is related to mutations in numerous genes encoding the structures of the inner ear in majority of the cases. Mutations in GJB2 gene are the most frequently identified causes of congenital nonsyndromal hearing loss. GJB2 gene testing became a routine clinical tool. For GJB2-negative patients new genetic approaches including methods based on new generation sequencing give a chance to identify mutations in other genes. The frequent reason of mild-to-moderate hearing loss such as the deletions/mutations of the gene STRC encoding stereocilin protein were recognized (OMIM: 606440). ObjectivesTo evaluate the audiological features in hearing impaired patients with deletions and point mutations in the STRC gene. Patients and methodsThe group of 28 patients from 21 unrelated families with pathological mutations in the STRC gene underwent audiological examination. The description and analysis of the results of full audiological examination was provided. ResultsAll patients initially had bilateral nonsyndromal sensorineural hearing loss. Among 11 homozygotes of large deletion harboring STRC to CATSPER2 genes were 7 male individuals indicating the presence of male infertility syndrome. In general, 7 children failed audiological screening and 4 children underwent audiological assessment in the age of 3 and 6 months. The most frequently hearing thresholds were registered between 35 and 55 dB that corresponds to mild-to-moderate hearing impairment. The average age of diagnostics was 7.9 years (ranged from 3 months to 45 years). In the majority of patients the audiological profiles were flat or descending with elevation of thresholds at middle and high frequencies and relatively preserved thresholds at low frequencies. Hearing thresholds are symmetric and stable with age. ConclusionSTRC-linked hearing loss is congenital, of mild and moderate severity. Special clinical and genetic approach for children who failed newborn hearing screening with mild-to-moderate hearing loss is necessary.

Application of Paper Folding Technique to Three-Dimensional Space Sound Absorber with Permeable Membrane: Case Studies of Trial Productions

The authors propose a space sound absorber made of a permeable membrane (PM), including woven or non-woven fabrics in three-dimensional shapes, e.g., cylinder, rectangle, etc. The proposed absorbers are examined by experimental measurements and boundary element analyses, and it is found that they can be effectively used especially for middle and high frequencies. In order to develop these absorbers for wider applications, it would be desirable to give them additional values and functions, particularly to elaborate on their design. Supposing that they could also be used for lighting equipment, such as lampshades as one of the applications, pilot studies on pseudo-cylindrical, and pseudo-spherical PM space absorbers with uneven surfaces produced by paper-folding (origami technique) are carried out. The pseudo-cylindrical concave curves (PCCC) shell shape has been proven as a suitable form for a lampshade, and the pseudo-spherical concave curves (PSCC) shell shape is an application of PCCC. In this paper, PCCC and PSCC shell shapes are applied to three-dimensional PM space absorbers, and trials are conducted using PMs selected by flow resistance measurements and preliminary simulations. The sound absorptivity of the specimens is measured in a reverberation chamber, and their absorptivity is 0.6 (PCCC case) and 0.4 (PSCC case) at mid-high frequencies.

Measurement of Wideband Absorbance as a Test for Otosclerosis.

The purpose of this study was to investigate the effectiveness of wideband energy absorbance in diagnosing otosclerosis by comparing the differences in acoustic absorbance between otosclerotic and normal ears. Exactly 90 surgically confirmed otosclerotic ears were included in the test group. The control group consisted of 126 matched normal-hearing subjects. The Titan hearing test platform (Interacoustics) was used for absorbance and acoustic immittance tests. Energy absorbance, measured at tympanometric peak pressure, was analyzed in the range 226–8000 Hz. Differences between normal and otosclerotic ears were analyzed in quarter-octave bands. Wideband absorbance, i.e., absorbance averaged over the 226–2000 Hz band, and resonance frequency were calculated and compared between normal and otosclerotic ears. Significant differences between the absorbance of normal and otosclerotic ears were found, especially at low and middle frequencies. No significant effect of ear side or gender was observed. For average wideband absorbance and resonance frequency, less pronounced (although significant) differences were found between normal and otosclerotic ears. Measurement of peak-pressure energy absorbance, averaged over a frequency band around 650 Hz, provides a valid criterion in testing for otosclerosis. The test is highly effective, with a sensitivity and specificity of over 85% and area under receiver operating characteristic curve above 0.9. Average wideband absorbance can also be used, but its effectiveness is lower. Other immittance-related measures are considerably less effective.

Video steganography based on DCT psychovisual and object motion

Steganography is a technique of concealing the message in multimedia data. Multimedia data, such as videos are often compressed to reduce the storage for limited bandwidth. The video provides additional hidden-space in the object motion of image sequences. This research proposes a video steganography scheme based on object motion and DCT-psychovisual for concealing the message. The proposed hiding technique embeds a secret message along the object motion of the video frames. Motion analysis is used to determine the embedding regions. The proposed scheme selects six DCT coefficients in the middle frequency using DCT-psychovisual effects of hiding messages. A message is embedded by modifying middle DCT coefficients using the proposed algorithm. The middle frequencies have a large hiding capacity and it relatively does not give significant effect to the video reconstruction. The performance of the proposed video steganography is evaluated in terms of video quality and robustness against MPEG compression. The experimental results produce minimum distortion of the video quality. Our scheme produces a robust of hiding messages against MPEG-4 compression with average NC value of 0.94. The proposed video steganography achieves less perceptual distortion to human eyes and it's resistant against reducing video storage.

Two-Dimensional Histogram Shifting-Based Reversible Data Hiding for H.264/AVC Video

Histogram shifting (HS) has been proved to be a great success in reversible data hiding (RDH). To reduce the quality loss of marked media and the increase in file size, several two-dimensional (2D) HS schemes based on the characteristics of cover media have been proposed recently. However, our analysis shows that the embedding strategies used in these methods can be further optimized. In this paper, two new 2D HS schemes for RDH in H.264/AVC video are developed, one of which uses the DCT coefficient pairs with both values 0 and the other does not. The embedding efficiency of a DCT coefficient pair in different embedding modes is firstly calculated. Then, based on the obtained embedding efficiency along with the statistical distribution of DCT coefficient pairs, two better embedding strategies are proposed. The secret data is finally embedded into the pairs of DCT coefficients of the middle and high frequencies using our proposed strategies. The comparison experiment results demonstrate that our schemes can achieve enhanced visual quality in terms of PSNR, SSIM, and entropy in most cases, and the increase in file size is smaller.

Observability Inequalities for Hermite Bi-cubic Orthogonal Spline Collocation Methods of 2-D Integro-differential Equations in the Square Domains

We will consider the problem of observability inequality of the Hermite bi-cubic orthogonal spline collocation space semi-discretizations of the 2-D integro-differential equations in the square domains. We prove the uniform (with respect to mesh-size) observability inequality in a subspace of solutions generated by the low frequencies of the negative part, and the middle frequencies of the positive part. Our method uses previously known uniform observability inequalities in the 1-d case and a dyadic spectral time decomposition. Some numerical results are presented to illustrate our theoretical analysis.

Design and implementation of accurate frequency estimator depend on deep learning

An Accurate, efficient, and stable system to estimate the unknown input frequency of a sinusoidal signal is presented. The proposed design solves the main drawback of the existing phase-based estimator which called a derivative estimator depend on deep learning. These limitations are the inability to estimate low frequencies and the large estimation errors for the frequencies near the Nyquist rate. A Brief mathematical analysis in discrete-time of the proposed system is presented. Proposed estimator performance when the input is a single sinusoid, multiple sinusoids in the presence of additive white Gaussian noise (AWGN) are provided. The accuracy of the proposed esti-mator is the result of dividing the dynamic range of estimation to three regions (low frequencies, middle frequencies, high frequencies) and specify a different formula to calculate the estimated frequency in each region. The boundaries of each region are determined by using a Grey wolf optimizer (GWO) which training bidirectional recurrent neural networks (BRNN) to select the best weights for the estimated frequency. The simulation results ensure the accuracy and validity of the proposed estimator compared to the traditional one. The hardware implementation of enhanced estimator using field-programmable gate array (FPGA), consumed 265 mW, and worked at 375 MHz. Â

Adaptive scaling factors based on the impact of selected DCT coefficients for image watermarking

Image watermarking technique aims at high imperceptibility of the embedded watermark with minimal distortion in the watermarked images. In frequency-domain, block-based Discrete Cosine Transform (DCT) is a popular method which can be improved by different scaling factors. This paper presents an adaptive scaling factor for selected DCT coefficients in image watermarking. The image blocks that have lowest pixel variances are chosen as the embedding locations. The optimal scaling factors for selected DCT coefficients on the middle frequencies are obtained by finding the best quality of images. The embedding process is performed using the obtained scaling factors. The proposed technique was investigated to verify the robustness and imperceptibility against various image-processing attacks. It is proved that our technique achieves higher robustness against noise addition, filter and compression than the existing schemes in most cases. Our technique produces greater imperceptibility than the existing schemes.

Impact of Phase Locked Loop with Different Types and Control Dynamics on Resonance of DFIG System

In recent years, the doubly fed induction generator (DFIG) operates in a weak grid, rather than a strong grid due to the high proportion of wind energy into the power grid. The impedance interaction between the DFIG system and series and parallel compensated weak grid might cause the subsynchronous resonance (SSR) and high frequency resonance (HFR) in the DFIG system, respectively. Phase locked loop (PLL) is a popular grid synchronization technique, and the high bandwidth PLL can cause resonance at middle frequencies in the DFIG system. However, the impact of PLL types and their controller dynamics on the resonance in the DFIG system are not adequately researched. The impact of the PLL controller with different types, such as synchronous reference frame (SRF) and Lead/Lag PLL, is studied in this paper to fill this gap. Additionally, an improved PLL is proposed, which can guarantee the high phase margin and decrease the likelihood of the resonance at middle frequencies in the DFIG system under a weak grid. Moreover, the phase margin of the DFIG system impedance with an improved PLL is less sensitive to its controller parameters. Simulation and experimental results verify the effectiveness of the proposed method.

The acoustic performance of circular openings and wall-mounted vents

Outdoor air intakes (vents) adversely affect the sound insulation of a building envelope. The purpose of the research was to investigate how different components of the wall-mounted vent and the vent-wall geometry influence its acoustic performance, and to provide practical guidelines that can be used in the design and testing of such devices. The study is based on laboratory measurements. Three basic questions are discussed: the test facility, the effect of a circular opening in a wall and the performance of a vent installed in the opening. A double partition wall should be used in the laboratory to suppress flanking transmission and provide reliable results. Low frequency modal effects related to a sample position in the wall did not influence the single number quantities. Circular openings exhibited fundamental resonance depending on the wall thickness, the diameter of the opening and the end reflection conditions. These effects contributed to the sound transmission loss of a complete vent. The vent components are effective mostly at high frequencies, as low frequency bands are controlled by the wall, while the improvement of middle frequencies is still a challenge. Aside from resonance, the combined sound insulation of particular vent components was approximately the same as that of the complete integrated unit.

Planar Monopole Antenna With a Parasitic Shorted Strip for Multistandard Handheld Terminals

A planar monopole antenna with a parasitic shorted strip for multistandard handheld terminal is presented. The proposed antenna simply consists of two overlapping strips: a long strip on the front side and a parasitic shorted strip on the back side. To make the proposed antenna easy to manufacture and reduce the manufacturing cost, the entire structure is fully printed without VIA holes, the long strip monopole is directly fed, and the parasitic shorted strip is coupled-fed by the overlapped part. For lower and middle frequencies, the GSM900 and PCS bands are excited by the fundamental mode of the long strip and the parasitic shorted strip, respectively. For the upper frequency, the Wi-Fi2400/RFID2450 and LTE2300/2500 bands are provided by the third-order mode of the long strip. The detailed design of the proposed antenna and its radiation performances are studied. The proposed multiband antenna occupies a small area of $40 \times 18$ mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> on a printed circuit board (PCB). The measured results show that the proposed antenna has three impedance bands with return loss less than -6 dB: 25.6% for the low band (850-1100 MHz), 13.3% for the middle band (1750-2000 MHz) and 22.7% for the high band (2190-2750 MHz).

A CASE OF MID-FREQUENCY SENSORINEURAL HEARING LOSS

Introduction: Mid-frequency sensorineural hearing loss (MFSNHL) is an unusual audiometric finding with a debatable etiology with unclear long-term results. In general, the middle frequencies are affected first, and the process progresses slowly to include all frequencies. There are also some cases where provocative factors have been reported. Purpose: The aim of the work is to present a clinical case in our practice of the rare occurrence of mid-frequency acoustic hearing loss and its diagnostic approach. Material and methods: The patient has undergone a number of manual and instrumental tests to confirm or reject a specific cause of the hearing loss condition. Results: A 52-year-old man was hospitalised with complaints of hearing loss for about a year, judging by the growing difficulty in making a phone call. Conclusions: Generally, a U-shaped audiogram is thought to indicate hearing loss of genetic origin. However, this type of deafness is not unique to one particular type of genetic mutation. There are also numerous descriptions of non-genetic mid-frequency hearing loss in the literature. In the particular clinical case presented by us, it was concluded that this was a hearing loss, possibly of hereditary nature, after excluding another provocative cause, as well as due to anamnestic data on premature hearing loss in one of the parents.

Microstructure Evolution and Impedance Analysis of 7YSZ Thermal Barrier Coating during Gas Thermal-Shock

Abstract A gas thermal-shock experiment of thermal barrier coating was carried out in air up to 1,250°C in order to simulate the thermal cycling process of the engine blades during the start heating and shut cooling. The growth of thermal growth oxide (TGO) layer and microstructure evolution of YSZ layer during thermal cycling process were investigated systematically by electrochemical impedance spectroscopy testing and scanning electron microscopy. The results show that the thickness of TGO layer increases when increasing the frequency of thermal cycling, and the impedance response of middle frequencies is more and more remarkable. Meanwhile, initiation and growth of microcracks occur in YSZ layer during the gas thermal-shock experiment. The corresponding impedance characterization of YSZ layer after 100 cycles is similar to the as-sprayed sample, indicating that the YSZ microcracks could heal in a short time when sintered at high temperature. But after 300 cycles, the impedance spectroscopy of YSZ layer is quite different from the as-sprayed sample, with the corresponding impedance of YSZ grain boundary becoming more and more remarkable when prolonging the thermal-shock times, indicating that unhealing microcracks form in the YSZ layer, which may be the main reason to induce the failure of YSZ layer.

Optical and psychophysical studies of the visual system of cosmonauts before and after long orbital flights

The changes in the spatial and frequency characteristics of the visual system, visual acuity, and the morphological structures of the macular zone of the retina in cosmonauts and pilots as a result of various gravitational loads were studied. We found that, after long space missions, cosmonauts exhibit a slight but statistically significant decrease in distance visual acuity, a significant decrease in contrast sensitivity mainly in the middle and low spatial frequencies, a decrease in the light sensitivity of the macular zone, a decrease in the optical density of the macular retinal pigment, and thickening of the chorioretinal layer. A pronounced decrease in contrast sensitivity in the low- and medium-spatial-frequency regions but an insignificant one in the high-spatial-frequency region and accordingly a small decrease in visual acuity indicate a disruption of the operation of the nerve structures of the visual analyzer, probably resulting from an increase in the level of internal noise. This increase in the level of internal noise in cosmonauts is associated with a prolonged exposure to microgravity, which causes a disruption of normal blood circulation.

Source shape impact on controlled source EM surveys

Impact of the shape of grounded-line sources on the frequency domain response observed in the controlled source electromagnetic (CSEM) method has not been addressed thoroughly. In this paper, we use the electromagnetic (EM) fields from a half space as examples to discuss the impact of shape. The EM fields from current dipoles along a curved source are summarized. To illustrate the impact, the ratios of the fields from a curved line source to that of a straight line source with the same current are computed. Numerical results show that the impact of source shape on EM fields occurs mainly from a few hertz to higher frequencies. In our examples, shape deformation causes about 7% variation in the real part, and up to a relative error of ~22.5% in the imaginary part at middle frequencies. However, for the derived impedance, the impact can be ignored. Spatially, in the coaxial zone, the impact of source curvature can also be ignored; but in the equatorial zone near the source, the impact needs to be considered. In our examples, the maximal distance between a curved source and the corresponding straight line source is about 1/4 of the spacing between two current poles, more curved than usually seen in field work. Therefore, our results indicate that we do not need to care about source shape when working in a far zone or with source curvature smaller than that of the sources here. There are two possible ways to lessen the shape impact. One is to lay out grounded line source in a Z shape, but a more complete way is by using impedance derived from orthogonal electrical and magnetic fields to present observed data.

Sustained-Release Triamcinolone Acetonide Hydrogels Reduce Hearing Threshold Shifts in a Model for Cochlear Implantation with Hearing Preservation

Introduction: In recent years, the preservation of residual hearing has become a major factor in patients undergoing cochlear implantation (CI). In studies attempting to pharmaceutically improve hearing preservation rates, glucocorticoids (GCs) applied perioperatively in many institutions have emerged as a promising treatment regimen. Although dexamethasone is most commonly used and has been applied successfully by various research groups, recently pharmacological properties have been reported to be relatively unsuitable for topical delivery to the inner ear. Consequently other glucocorticoids merit further evaluation. The aim of this study was therefore to evaluate the otoprotective effects of the topical application of a sustained-release triamcinolone acetonide (TAAC) hydrogel in CI with hearing preservation. Methods: Normal-hearing pigmented guinea pigs were randomized into a group receiving a single dose of a 6% TAAC poloxamer 407 hydrogel, a group receiving a 30% TAAC hydrogel and a control group. All hydrogel applications were performed 1 day prior to CI. After a cochleostomy was drilled, a specifically designed silicone electrode was inserted into the scala tympani for 5 mm. Frequency-specific compound action potentials of the auditory nerve (0.5–32 kHz) were measured pre- and directly postoperatively as well as on days 3, 7, 14, 21, and 28. Finally, temporal bones were harvested for histological evaluation. Results: Application of the TAAC hydrogels resulted in significantly reduced hearing threshold shifts in low, middle and high frequencies and improved spiral ganglion cell survival in the second turn of the cochlea. Outer hair cell numbers in the basal and second turn of the cochlea were slightly reduced after TAAC application. Conclusion: In summary, we were able to demonstrate functional benefits of a single preoperative application of a TAAC hydrogel in a guinea pig model for CI, which persisted until the end of the observational period, that is, 28 days after surgery.

Repair of subtotal tympanic membrane perforations: A temporal bone study of several tympanoplasty materials.

The aim of this project was to investigate the effects of different types of graft material, and different remaining segments of the native TM on its motion. In twelve human temporal bones, controlled TM perforations were made to simulate three different conditions. (1) Central perforation leaving both annular and umbo rims of native TM. (2) Central perforation leaving only a malleal rim of native TM. (3) Central perforation leaving only an annular rim of native TM. Five different graft materials (1) perichondrium (2) silastic (3) thin cartilage (4) thick cartilage (5) Lotriderm® cream were used to reconstruct each perforation condition. Umbo and stapes vibrations to acoustic stimuli from 250 to 6349 Hz were measured using a scanning laser Doppler vibrometer. Results showed that at low frequencies: in the Two Rims condition, all grafting materials except thick cartilage and Lotriderm cream showed no significant difference in umbo velocity from the Normal TM, while only Lotriderm cream showed a significant decrease in stapes velocity; in the Malleal Rim condition, all materials showed a significant decrease in both umbo and stapes velocities; in the Annular Rim condition, all grafting materials except Lotriderm and perichondrium showed no significant difference from the Normal TM in stapes velocity. Umbo data might not be reliable in some conditions because of coverage by the graft. At middle and high frequencies: all materials showed a significant difference from the Normal TM in both umbo and stapes velocities for all perforation conditions except in the Annular Rim condition, in which silastic and perichondrium showed no significant difference from the Normal TM at umbo velocity in the middle frequencies. In the low frequencies, the choice of repair material does not seem to have a large effect on sound transfer. Our data also suggests that the annular rim could be important for low frequency sound transfer.

On-Line Compensation for the Disturbance Rejection Rate of a Platform Seeker Based on a High-Gain Extended State Observer

This paper focuses on the on-line compensation of the disturbance rejection rate (DRR) for a platform seeker. The mathematical model of the typical platform seeker based on the inertial space is established, and the line-of-sight (LOS) rate from different signal extraction points is strictly derived. Considering the spring torque disturbance and damping torque disturbance caused by the missile attitude motion, the seeker DRR transfer functions are deduced and the amplitude and phase characteristics at different frequencies are also analyzed. In order to close the engineering practice, the DRR parasitic loop (DRRPL) model of the seeker is rationally simplified and the stable region of the parasitic loop from different extraction points is also obtained. However, to increase the stability and guidance accuracy of the missile terminal flight, the compensation scheme based on the high-gain extended state observer (ESO) is used to estimate the disturbance torques and eliminate the seeker DRR effect. Numerical simulations are conducted to verify the effectiveness of the proposed scheme. The simulation results show that the seeker DRR effect mainly exists in the middle and low frequencies and the stable region of the parasitic loop at different signal extraction points is different. The proposed compensation scheme can effectively eliminate the parasitic loop effect of the seeker and increase the flight stability of the missile. It can reduce the terminal miss distance of the missile and improve the strike accuracy.

Mole senses.

Many people are familiar with the meandering tunnels of moles, far fewer are familiar with the creatures that made them. Such secrecy is, of course, one of the great benefits of burrowing through the earth where few predators can follow. But it's not the only benefit. Soil contains a smorgasbord of nutritious invertebrate prey - hence all the tunneling. In fact the richness of the soil niche has given rise to a diversity of mole species that could be said to resemble the evolutionary diversification of bats, though on a smaller scale. In both cases, mammals have evolved a suite of unique anatomical traits (coincidentally involving modification of the forelimb) that allows them to exploit a huge resource of invertebrate prey that is largely inaccessible to their competitors. For bats the thin, delicate wings were the key innovation, for moles the forelimbs have undergone a similarly dramatic structural shift, but in the opposite direction - the bones have become short, stout, and powerful to act as shovels.

Effect of Hybrid Alumina/Aluminium Foil Dome Diaphragms on Sound Performance of Loudspeaker

Plasma electrolytic oxidation (PEO) technology enables to fabricate a nanostructured ceramic top layer on an aluminium foil, called hybrid alumina/aluminium material, which has the enhanced properties like hardness, stiffness, wear resistance and corrosion resistance. In this work, PEO nanostructured coatings were applied to aluminium speaker domes to study what effects PEO coatings could offer. A set of treated domes were processed to have a thin coating and the other processed to have a thicker coating. Afterwards, the speaker domes were conducted with several tests and measurements. From the frequency range of a low frequency (200 Hz to 5 kHz) there was very little downside to adding the coating, only at middle frequencies (5 kHz to 12 kHz) a slight decrease in sensitivity can be found. In high range frequencies (12 kHz to 14 kHz) the sensitivity in dampening and sound distortion resistance was increased. In general, these qualities should lead to a better, cleaner sound quality reproduction.