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Journal of Voice : Official Journal of... Jan 2020The change in the spectrum of sustained /a/ vowels was mapped over the voice range from low to high fundamental frequency and low to high sound pressure level (SPL), in...
The change in the spectrum of sustained /a/ vowels was mapped over the voice range from low to high fundamental frequency and low to high sound pressure level (SPL), in the form of the so-called voice range profile (VRP). In each interval of one semitone and one decibel, narrowband spectra were averaged both within and across subjects. The subjects were groups of 7 male and 12 female singing students, as well as a group of 16 untrained female voices. For each individual and also for each group, pairs of VRP recordings were made, with stringent separation of the modal/chest and falsetto/head registers. Maps are presented of eight scalar metrics, each of which was chosen to quantify a particular feature of the voice spectrum, over fundamental frequency and SPL. Metrics 1 and 2 chart the role of the fundamental in relation to the rest of the spectrum. Metrics 3 and 4 are used to explore the role of resonances in relation to SPL. Metrics 5 and 6 address the distribution of high frequency energy, while metrics 7 and 8 seek to describe the distribution of energy at the low end of the voice spectrum. Several examples are observed of phenomena that are difficult to predict from linear source-filter theory, and of the voice source being less uniform over the voice range than is conventionally assumed. These include a high-frequency band-limiting at high SPL and an unexpected persistence of the second harmonic at low SPL. The two voice registers give rise to clearly different maps. Only a few effects of training were observed, in the low frequency end below 2 kHz. The results are of potential interest in voice analysis, voice synthesis and for new insights into the voice production mechanism.
Topics: Acoustics; Female; Humans; Male; Phonation; Singing; Sound Spectrography; Voice Quality
PubMed: 30269894
DOI: 10.1016/j.jvoice.2018.08.014 -
Applied Acoustics. Acoustique Applique.... Jun 2022The aviation industry has seen dramatic growth over the decades till the recent disruption due to the COVID-19 pandemic. Moreover, long-haul routes with a distance of...
The aviation industry has seen dramatic growth over the decades till the recent disruption due to the COVID-19 pandemic. Moreover, long-haul routes with a distance of more than 4000 km are common for major airlines worldwide. Therefore, aircraft cabin noise assessment is essential, especially in long-haul flights, for passenger and flight crew health wellness. In this paper, the cabin noise of five wide-body aircraft, namely Airbus A330-300ER, A350-900, A380-800, and Boeing B777-200ER and B787-900, was recorded using a calibrated in-house developed smartphone application. The sound pressure levels of in-cabin noise have been measured on two different decibel scales, namely, A-weighted [dB(A)] and C-weighted scales [dB(C)]. The sound pressure levels of Airbus A380-800 were lowest among selected models, while the in-cabin pressure level values of Airbus A350-900 were maximum. However, the difference in decibel levels between the aircraft is minimal as it is within 3 dB.
PubMed: 35540109
DOI: 10.1016/j.apacoust.2022.108809 -
Noise & Health 2017Infrasound is a mechanical vibration wave with frequency between 0.0001 and 20 Hz. It has been established that infrasound of 120 dB or stronger is dangerous to...
INTRODUCTION
Infrasound is a mechanical vibration wave with frequency between 0.0001 and 20 Hz. It has been established that infrasound of 120 dB or stronger is dangerous to humans. However, the biological effects of low decibel infrasound are largely unknown. The purpose of this study was to investigate the effects of low decibel infrasound on the cardiac fibroblasts.
MATERIALS AND METHODS
The cardiac fibroblasts were isolated and cultured from Sprague-Dawley rats. The cultured cells were assigned into the following four groups: control group, angiotensin II (Ang II) group, infrasound group, and Ang II+infrasound group. The cell proliferation and collagen synthesis rates were evaluated by means of [3H]-thymidine and [3H]-proline incorporation, respectively. The levels of TGF-β were determined by enzyme-linked immunosorbent assay. Moreover, RNAi approaches were used for the analysis of the biological functions of miR-29a, and the phosphorylation status of Smad3 was detected using western blotting analysis.
RESULTS
The results showed that low decibel infrasound significantly alleviated Ang II-induced enhancement of cell proliferation and collagen synthesis.
DISCUSSION
Compared with the control, Ang II markedly decreased the expression of miR-29a levels and increased the secretion of TGF-β and phosphorylation of Smad3, which was partly reversed by the treatment with low decibel infrasound. Importantly, knockdown of miR-29a diminished the effects of infrasound on the cardiac fibroblasts. In conclusion, low decibel infrasound inhibits Ang II-stimulated cardiac fibroblasts via miR-29a targeting TGF-β/Smad3 signaling.
Topics: Angiotensin II; Animals; Cell Proliferation; Cells, Cultured; Collagen; Enzyme-Linked Immunosorbent Assay; Fibroblasts; MicroRNAs; Myocardium; Phosphorylation; Proline; RNA Interference; Rats; Rats, Sprague-Dawley; Real-Time Polymerase Chain Reaction; Signal Transduction; Smad3 Protein; Thymidine; Transforming Growth Factor beta; Tritium; Vibration
PubMed: 28615545
DOI: 10.4103/nah.NAH_14_16 -
Revista Brasileira de Medicina Do... Mar 2021music is performed with specific drums, which produce loud and low-tone sounds that can potentially lead to hearing risk.
INTRODUCTION
music is performed with specific drums, which produce loud and low-tone sounds that can potentially lead to hearing risk.
OBJECTIVES
To assess sound pressure levels and hearing safety of musicians who play in groups.
METHODS
Using a decibel meter, noise exposure was measured in two different groups (group 1 and group 2), which are divided into categories: (group 1 = five categories - junior, free, general a, general b, and master, and group 2 = two categories - adult and child). The calculation of the daily noise dose was based on the Brazilian Occupational Hygiene Standard 01, which establishes the following classification: acceptable dose (between 0 and 50%), above the action level (50 to 80%), uncertain dose level (80 to 100%), and above the acceptable level (more than 100%).
RESULTS
In group 1 categories, the daily noise doses obtained were: junior = 88%; general B = 423%; master = 218%; general A = 370%, and free = 150%. In the adult and children categories of group 2, the results were 127 and 17%, respectively.
CONCLUSIONS
musicians are exposed to daily noise doses above the safe level, except for the junior categories in group 1, and the children, in group 2 - which showed daily noise doses at an uncertain dose level, and at an acceptable level, respectively.
PubMed: 33688328
DOI: 10.47626/1679-4435-2020-591 -
Frontiers in Medicine 2022Despite many studies in the field examining excessive noise in the intensive care unit, this issue remains an ongoing problem. A limiting factor in the progress of the...
BACKGROUND
Despite many studies in the field examining excessive noise in the intensive care unit, this issue remains an ongoing problem. A limiting factor in the progress of the field is the inability to draw conclusions across studies due to the different and poorly reported approaches used. Therefore, the first goal is to present a method for the general measurement of sound pressure levels and sound sources, with precise details and reasoning, such that future studies can use these procedures as a guideline. The two procedures used in the general method will outline how to record sound pressure levels and sound sources, using sound level meters and observers, respectively. The second goal is to present the data collected using the applied method to show the feasibility of the general method and provide results for future reference.
METHODS
The general method proposes the use of two different procedures for measuring sound pressure levels and sound sources in the intensive care unit. The applied method uses the general method to collect data recorded over 24-h, examining two beds in a four-bed room, via four sound level meters and four observers each working one at a time.
RESULTS
The interrater reliability of the different categories was found to have an estimate of >0.75 representing good and excellent estimates, for 19 and 16 of the 24 categories, for the two beds examined. The equivalent sound pressure levels (L) for the day, evening, and night shift, as an average of the sound level meters in the patient room, were 54.12, 53.37, and 49.05 dBA. In the 24-h measurement period, talking and human generated sounds occurred for a total of 495 (39.29% of the time) and 470 min (37.30% of the time), at the two beds of interest, respectively.
CONCLUSION
A general method was described detailing two independent procedures for measuring sound pressure levels and sound sources in the ICU. In a continuous data recording over 24 h, the feasibility of the proposed general method was confirmed. Moreover, good and excellent interrater reliability was achieved in most categories, making them suitable for future studies.
PubMed: 35733869
DOI: 10.3389/fmed.2022.836203 -
Ophthalmology Science Jun 2023Complement C1q, the initiating molecule of the classical complement cascade, is involved in synapse elimination and neuronal loss in neurodegenerative diseases including...
PURPOSE
Complement C1q, the initiating molecule of the classical complement cascade, is involved in synapse elimination and neuronal loss in neurodegenerative diseases including glaucoma. Here we report an evaluation of the safety, tolerability, and ocular pharmacokinetics (PK) and pharmacodynamics of intravitreal (IVT) injections of ANX007, an anti-C1q monoclonal antibody fragment that blocks activation of the classical complement cascade.
DESIGN
An open-label, single-dose-escalation phase Ia study followed by a double-masked, randomized, sham-controlled, repeat-injection phase Ib study.
PARTICIPANTS
A total of 26 patients with primary open-angle glaucoma.
METHODS
Nine patients with primary open-angle glaucoma (mean Humphrey visual field deviation between -3 and -18 decibels [dB]) were enrolled in phase Ia and received single doses of ANX007 (1.0 mg, n = 3; 2.5 mg, n = 3; or 5.0 mg, n = 3). Seventeen patients (mean Humphrey visual field deviation between -3 and -24 dB) were enrolled in phase Ib and randomized to 2 monthly doses of ANX007 (sham, n = 6; 2.5 mg ANX007, n = 6; or 5 mg ANX007, n = 5).
MAIN OUTCOME MEASURES
Safety and tolerability (including laboratory evaluation of urinalysis, complete blood count, and serum chemistries), ANX007 PK, target engagement, and immunogenicity.
RESULTS
The mean age overall was 70 years in phase Ia and 68 years in phase Ib. In both studies, no serious adverse events were observed, no non-ocular treatment-emergent adverse events (TEAEs) attributable to study drug were reported, and ocular TEAEs were mild. Intraocular pressure returned to normal levels for all patients within 45 minutes of IVT injection. No clinically significant deviations in laboratory results were observed. In the phase Ib study, C1q in the aqueous humor was reduced to undetectable levels in both the 2.5 mg and 5 mg cohorts 4 weeks after the first ANX007 dose.
CONCLUSIONS
In these studies, single and repeat IVT ANX007 injections were well tolerated and demonstrated full target engagement 4 weeks after dosing with both low and high doses, supporting monthly or less-frequent dosing. Further investigation in neurodegenerative ocular diseases is warranted.
FINANCIAL DISCLOSURES
Proprietary or commercial disclosure may be found after the references.
PubMed: 37124168
DOI: 10.1016/j.xops.2023.100290 -
Computational Intelligence and... 2023LoRa is an ISM-band based LPWAN communication protocol. Despite their wide network penetration of approximately 20 kilometers or higher using lower than 14 decibels... (Review)
Review
LoRa is an ISM-band based LPWAN communication protocol. Despite their wide network penetration of approximately 20 kilometers or higher using lower than 14 decibels transmitting power, it has been extensively documented and used in academia and industry. Although LoRa connectivity defines a public platform and enables users to create independent low-power wireless connections while relying on external architecture, it has gained considerable interest from scholars and the market. The two fundamental components of this platform are LoRaWAN and LoRa PHY. The consumer LoRaWAN component of the technology describes the network model, connectivity procedures, ability to operate the frequency range, and the types of interlinked gadgets. In contrast, the LoRa PHY component is patentable and provides information on the modulation strategy which is being utilized and its attributes. There are now several LoRa platforms available. To create usable LoRa systems, there are presently several technical difficulties to be overcome, such as connection management, allocation of resources, consistent communications, and security. This study presents a thorough overview of LoRa networking, covering the technological difficulties in setting up LoRa infrastructures and current solutions. Several outstanding challenges of LoRa communication are presented depending on our thorough research of the available solutions. The research report aims to stimulate additional research toward enhancing the LoRa Network capacity and allowing more realistic installations.
Topics: Communication; Industry; Technology
PubMed: 36654727
DOI: 10.1155/2023/5183062