This paper reports on the long-term statistics of ambient noise (50-2000 Hz) in the northeast South China Sea. The data were collected from July 2016 to March 2018. The long-term statistics, seasonal, and diel variations of ambient noise are analyzed. There are significant seasonal variations from 500 to 2000 Hz. The ambient noise level at 1000 Hz is 6-10 dB higher in winter than in summer. There is only a small difference between the day and night comparison (less than 1.6 dB). The results are significant to evaluate and improve the performance of underwater acoustic systems in this area.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1121/1.5110740 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Dual-Gas Sensor Employing Wavelength-Stabilized Tunable Diode Laser Absorption Spectroscopy and H-Infinity Filtering Algorithm.
Appl Spectrosc
January 2025
School of Mathematics Physics and Finance, Anhui Polytechnic University, Wuhu, China.
A compact dual-gas sensor based on the two near-infrared distributed feedback diode lasers and a multipass cell has been established for the simultaneous measurement of methane (CH) and acetylene (CH). The time division multiplexing calibration-free direct absorption spectroscopy is used to eliminate the cross interference in the application of multicomponent gas sensors. A wavelength stabilization technique based on the proportion integration differentiation feedback control is developed to suppress laser wavelength drift and an H-infinity (H) filter algorithm to reduce the system noise.
View Article and Find Full Text PDFComparison of coseismic velocity changes estimated by cross-correlation of ambient seismic noise for earthquakes in south Korea and Japan.
Sci Rep
January 2025
Centre for Earthquake Studies, National Centre for Physics, Islamabad, 44000, Pakistan.
Ambient noise cross-correlation has been widely used to observe post-earthquake temporal velocity variations. Comparative studies are essential for assessing seismic hazards and clarifying the relationship between velocity variation and magnitude. However, very few comparative studies by earthquake magnitude have been conducted, particularly for magnitudes smaller than 6.
View Article and Find Full Text PDFEffect of the Levels and Sources of Noise on the Sleep Quality of Conscious Patients in Emergency Intensive Care Unit.
Noise Health
January 2025
Department of EICU, Wenzhou Central Hospital; The Dingli Clinical College of Wenzhou Medical University, Wenzhou, Zhejiang Province, China.
Purpose: This study aimed to assess the levels and sources of noise in the emergency intensive care unit (EICU) of an emergency department and investigate their effects on the sleep quality of conscious patients.
Methods: A study was conducted on patients admitted to the EICU from December 2020 to December 2023. They were categorised according to their sleep quality with the Pittsburgh Sleep Quality Index.
A combined noise source model based on vertical coherence to quantify the proportions of two types of noise power.
J Acoust Soc Am
January 2025
National Key Laboratory of Underwater Acoustic Technology, Harbin Engineering University, Harbin 150001, China.
With the vigorous development of maritime trade, the frequency band from 100 to 1500 Hz of shallow-sea ambient noise is not only affected by surface wind-induced noise but also the contribution of ship noise. Shallow-sea ambient noise can be described by a linear combination of surface wind-induced noise sources and ship noise sources. By using the correspondence between the real part of the vertical coherence and vertical energy flux, this work establishes a combined noise source model based on vertical coherence.
View Article and Find Full Text PDFNoise Reduction in Abdominal Acoustic Recordings of Maternal Placental Murmurs.
Biomed Phys Eng Express
January 2025
Department of Health Science and Technology, Aalborg University, Selma Lagerløfs Vej 249, Aalborg, 9260, DENMARK.
Unlabelled: Fetal phonocardiography is a well-known auscultation technique for evaluation of fetal health. However, murmurs that are synchronous with the maternal heartbeat can often be heard while listening to fetal heart sounds. Maternal placental murmurs (MPM) could be used to detect maternal cardiovascular and placental abnormalities, but the recorded MPMs are often contaminated by ambient interference and noise.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!