Acoustic environment of admiralty inlet: Broadband noise measurements

2011 ◽  
Author(s):  
Jinshan Xu ◽  
Z Daniel Deng ◽  
Jayson J Martinez ◽  
Thomas J Carlson ◽  
Joshua R Myers ◽  
...  
Keyword(s):  
Broadband Noise ◽  
Acoustic Environment ◽  
Noise Measurements ◽  
Admiralty Inlet

Geoecological assessment of acoustic screens using for protection residential areas when transportation minerals by rail

2017 ◽  
pp. 36-43
Author(s):  
Olga Kopytenkova ◽  
Dmitriy Kurepin ◽  
Ekaterina Vereshchagina
Keyword(s):  
Practical Importance ◽  
Reference Conditions ◽  
Measurement Data ◽  
Excess Noise ◽  
Normative Values ◽  
Residential Areas ◽  
Acoustic Environment ◽  
Allowable Level ◽  
Noise Measurements ◽  
Standard Values

Objective: Аssessment of acoustic screens effectiveness for protection residential areas when transportation minerals by rail. Methods: The experiment, simulation of acoustic environment. Results: Оne of the main problems of big cities is protection of population from excessive noise. To assess the acoustic screens effectiveness for protection residential areas when transportation minerals by rail were carried out noise measurements at the station Pontoon. The obtained measurement data show that the excess noise above the standard values. Therefore, to reduce noise it is necessary to conduct anti-noise measures. One of the most common means of reducing the noise of rail transport, is the use of acoustic screens. In the work carried out simulation of an acoustic screen using the program «Acoustics» at the following reference conditions: acoustic screen with a height of 5 m were installed on the site along houses № 13–16, 18, 19 A. Titenko Str (railway station Pontoon); design points were taken at a distance of not less than 1 m from the facade of buildings. The obtained simulation results show that normative values are reached only at the height of the calculation points is up to 5 m. With increasing elevation there is growing noise beyond the maximum permissible level. Research shows that the acoustic screen would be effective only at the level of 1–2 floors of the building. Low screen efficiency with increasing altitude is due to the missing in the sound area of the shadow calculated points located above 5 m. Practical importance: Revision of existing noise regulations of the railway transport in the direction of increasing the maximum allowable level by using amendments, can reduce complaints of noise from rail freight transport (in particular carrying solid minerals).

scholarly journals Efficacy of Sound Therapy for Tinnitus Using an Enriched Acoustic Environment with Hearing-Loss Matched Broadband Noise

2022 ◽  
Vol 12 (1) ◽  
pp. 82
Author(s):  
María Cuesta ◽  
Christiam Garzón ◽  
Pedro Cobo
Keyword(s):  
Hearing Loss ◽  
Chronic Condition ◽  
Broadband Noise ◽  
Sound Stimulus ◽  
Severity Scale ◽  
Acoustic Environment ◽  
Tinnitus Severity ◽  
Baseline Severity ◽  
Sound Therapy ◽  
Tinnitus Distress

Background: Tinnitus is a rather heterogeneous chronic condition/disorder which is difficult to treat. Some tinnitus treatments combine sound therapy with counselling. The main goal of this study is to report the efficacy of a customized sound therapy combined with counselling on a cohort of 83 tinnitus patients. Methods: 119 tinnitus subjects, recruited between January 2018 and June 2021, were subjected to a treatment consisting of a combination of an initial counselling session and four-month sound therapy. The sound stimulus was a personalized broadband noise colored by the audiometry of the subjects. These stimuli were given to the patients in mp3 format to be heard 1 h per day over 4 months. The tinnitus severity of the patients was evaluated monthly through the validated Spanish version of the Tinnitus Handicap Inventory. Results: Of the patients, 30% (36 of 119) withdrew from the treatment before finishing, and 96% (80 of 83) of the subjects completing the therapy attained some relief after 4 months. The overall average THI decrease of these 80 participants was 23. However, when the THI was analyzed by severity scales, it was found that patients with initial mild, moderate, severe and catastrophic handicap had an average THI decrease of 14, 20, 31 and 42 points, respectively. Thus, the average THI decrease depended on the baseline severity scale of patients. Conclusions: Consequently, the proposed treatment was demonstrated to be effective in providing clinically relevant relief in tinnitus distress patients in just 4 months.

scholarly journals Proposition of an attenuating solution for noise pollution caused by telecommunications installations and systems in urban environments

2021 ◽  
Vol 9 (71) ◽  
Author(s):  
Paulo Henrique Trombetta Zannin ◽  
Erik de Lima Andrade
Keyword(s):  
Cooling System ◽  
Residential Building ◽  
Noise Pollution ◽  
Urban Environments ◽  
National Standard ◽  
Maximum Speed ◽  
Acoustic Environment ◽  
Sound Levels ◽  
Before And After ◽  
Noise Measurements

This study evaluates the noise generated by metallic cabinets of telecommunications transmission stations, before and after the implementation of a sound attenuator. The first step consisted of installing the attenuating system, which consisted of a glass wool plate on top of a metal cabinet. Then, we compared the results with a cabinet without the installation of the system. The speeds of the cooling system of the cabinets were the average and maximum. Noise measurements followed the guidelines of NBR 10151, and the acoustic descriptor used was the mean equivalent level (Leq). After verifying the effectiveness of the installation of the system in sound attenuation, several cabinets were adapted in installations located in two cities in southern Brazil. One installation was located in a residential area, with houses on its surroundings, and the other on top of a residential building. The study showed that the attenuating system was effective in reducing the noise generated by the cabinets, both at average and at maximum speed, in both locations. Although the final sound levels did not reach those recommended by the national standard NBR 10151, of acoustic comfort for communities, residents close to the facilities reported an improvement in the local acoustic environment.

scholarly journals Estimation of the lower cut-off frequency of an anechoic chamber: An empirical approach

2020 ◽  
Vol 19 (1-2) ◽  
pp. 57-72
Author(s):  
Singh K Sushil ◽  
Mohit Garg ◽  
S Narayanan
Keyword(s):  
Sound Source ◽  
Calibration Procedure ◽  
Broadband Noise ◽  
Anechoic Chamber ◽  
Chamber Wall ◽  
Empirical Expression ◽  
Inverse Square Law ◽  
Total Distance ◽  
Chamber Volume ◽  
Noise Measurements

This paper deals with the development of an empirical expression to determine the lower cut-off frequency of an anechoic chamber when the source volume, chamber volume, wedge height as well as the major dimensions (i.e., total distance between the source and the chamber wall) are known. The frequency obtained from the empirical expression compares well within ±3% of the lower cut-off frequency obtained from the experiments. The paper also addresses the construction details and calibration procedure of the anechoic chamber. The chamber is calibrated by verifying the inverse square law for different directions from the sound source, and the lower cut-off frequency of the chamber is found to be 315 Hz within ±0.5 dB. Further, the fan broadband noise measurements are made, inside and outside, of the anechoic chamber in order to demonstrate the echo-free nature of the chamber and the spectra clearly shows that the chamber is anechoic for a broad range of frequencies.

Early life exposure to noise alters the representation of auditory localization cues in the auditory space map of the barn owl

2011 ◽  
Vol 105 (5) ◽  
pp. 2522-2535 ◽  
Author(s):  
Adi Efrati ◽  
Yoram Gutfreund
Keyword(s):  
Noise Exposure ◽  
Matched Control ◽  
Extended Period ◽  
Broadband Noise ◽  
Auditory Localization ◽  
Neural Representation ◽  
Acoustic Environment ◽  
Auditory Space ◽  
Auditory Space Map ◽  
Interaural Level Differences

The auditory space map in the optic tectum (OT) (also known as superior colliculus in mammals) relies on the tuning of neurons to auditory localization cues that correspond to specific sound source locations. This study investigates the effects of early auditory experiences on the neural representation of binaural auditory localization cues. Young barn owls were raised in continuous omnidirectional broadband noise from before hearing onset to the age of ∼65 days. Data from these birds were compared with data from age-matched control owls and from normal adult owls (>200 days). In noise-reared owls, the tuning of tectal neurons for interaural level differences and interaural time differences was broader than in control owls. Moreover, in neurons from noise-reared owls, the interaural level differences tuning was biased towards sounds louder in the contralateral ear. A similar bias appeared, but to a much lesser extent, in age-matched control owls and was absent in adult owls. To follow the recovery process from noise exposure, we continued to survey the neural representations in the OT for an extended period of up to several months after removal of the noise. We report that all the noise-rearing effects tended to recover gradually following exposure to a normal acoustic environment. The results suggest that deprivation from experiencing normal acoustic localization cues disrupts the maturation of the auditory space map in the OT.

scholarly journals Modal Analysis for Global Control of Broadband Noise in a Rectangular Enclosure

2007 ◽  
Vol 26 (2) ◽  
pp. 91-104 ◽  
Author(s):  
Allahyar Montazeri ◽  
Javad Poshtan ◽  
Mohammad Hossein Kahaei
Keyword(s):  
Modal Analysis ◽  
Controller Design ◽  
Broadband Noise ◽  
Sensors And Actuators ◽  
Noise Sources ◽  
Control Effort ◽  
Acoustic Environment ◽  
Rectangular Enclosure ◽  
Simulation Results ◽  
Degenerate Modes

Modal analysis for examination of the possibility of the global reduction of broadband noise in a rectangular enclosure has been studied in this paper. By developing a modal model of the acoustic environment of the enclosure the shape modes and their frequencies are obtained and on suitable bandwidth for the controller design is calculated. In order to simplify the analysis the noise sources are assumed localized and internal in one corner of the kiosk. The analysis results show that due to the existence of some degenerate modes in this application, the control action is complicated. Simulation results demonstrate how positions and number of loudspeakers and microphones will change the performance of the controller and its corresponding control effort. Based on these results and analysis a reasonable size for the controller and proper locations for sensors and actuators are proposed. Simulation results also confirm the effectiveness of the proposed system in reduction of the acoustic potential energy in the kiosk.

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