MEMS digital microphone and Arduino compatible microcontroller: an embedded system for noise monitoring

2021 ◽  
Vol 263 (3) ◽  
pp. 3921-3932
Author(s):  
Felipe Ramos de Mello ◽  
William D'Andrea Fonseca ◽  
Paulo Henrique Mareze
Keyword(s):  
Embedded System ◽  
Cost Effective ◽  
Sound Level ◽  
Early Career ◽  
Iir Filters ◽  
Sound Levels ◽  
Mems Microphone ◽  
Noise Assessment ◽  
Assessment And Monitoring ◽  
Level Meter

Noise assessment and monitoring are essential parts of an acoustician's work since it helps to understand the environment and propose better solutions for noise control and urban noise management. Traditionally, equipment to carry out this task is standardized, and, eventually, expensive for the early career professional. This work develops a high-quality (and cost-effective) prototype for an embedded noise monitoring device based upon a digital I2S MEMS microphone and an Arduino compatible microcontroller, named Teensy. Its small size and low power consumption are also advantages designed for the project. The system captures and processes sound in real-time, computes A and C frequency-weighted equivalent sound levels, along with time-weighted instant levels with a logging interval of 125 ms. Part of the software handles the audio environment, while the biquadratic IIR filters present in the Cortex Microcontroller library are responsible for the frequency- and time-weightings - using floating-point for enhanced precision. The prototype results were compared against a Class 2 Sound Level Meter, rendering very similar results for the tested situations, proving a powerful and reliable tool. Improvements and further testing are also being conducted to refine its functioning and characterization. Ultimately, the prototype achieved promising performance, confirming as a solution for noise monitoring.

Applications of Sound Intensity Measurements to Gas Turbine Engineering

1992 ◽  
Author(s):  
R. D. Rawlinson
Keyword(s):  
Gas Turbine ◽  
Sound Intensity ◽  
Cost Effective ◽  
Sound Level ◽  
Directional Sensitivity ◽  
Noise Sources ◽  
Offshore Installations ◽  
Practical Reality ◽  
Detailed Assessment ◽  
Level Meter

Recent advances in signal processing techniques have made the measurement of sound intensity a practical reality. The newly developed sound intensity meters can indicate both the magnitude and direction of sound. This is a major advantage over the traditional sound level meter which does not have such directional sensitivity. Sound intensity meters can, therefore, make accurate measurements under adverse conditions, such as onshore or offshore, where sound level meters may be unsuitable. This makes the detailed assessment of the sound power output of a gas turbine package, operating in the field, practicable. Individual components of a gas turbine train can be evaluated so that the dominant noise sources can be identified, thereby providing more cost effective solutions to onshore and offshore installations. This paper describes briefly the concepts of sound intensity, the current state of standards and some aspects of measurement technique. Case histories of the use of sound intensity instrumentation in a variety of situations, relevant to gas turbine engineering, will be described. This will include laboratory and field based investigations.

Can permanent sensorineural hearing loss be caused by sleeping with an ear against a train window?

2002 ◽  
Vol 116 (9) ◽  
pp. 695-698 ◽  
Author(s):  
Alasdair Robertson ◽  
Brian Bingham ◽  
George McIlwraith
Keyword(s):  
Hearing Loss ◽  
Sensorineural Hearing Loss ◽  
Sound Level ◽  
Sensorineural Hearing ◽  
Sound Levels ◽  
Falling Asleep ◽  
Short Period ◽  
Sufficient Intensity ◽  
Level Meter ◽  
Moving Train

A patient presented to the authors with unilateral sensorineural hearing loss after falling asleep with his ear tightly pressed against a window of a moving train. This study set out to determine whether a train could generate sound levels of sufficient intensity to cause such a hearing loss. A sound level meter was used to measure the sound levels produced at the window of a moving train. Further measurements were made with a rubber attachment on the microphone, that simulated the effect of the ear stuck to the window. The sound levels were found to be amplified by the attachment but not to levels that could cause a hearing loss over a short period. In a second experiment eight healthy volunteers all perceived an increase in sound levels when their ears were pressed against a train window.It seems unlikely that sleeping with an ear against a train window can cause hearing loss, but it cannot be ruled out.

Decibel levels during extracorporeal lithotripsy for salivary stones

2008 ◽  
Vol 122 (12) ◽  
pp. 1305-1308 ◽  
Author(s):  
M H Fritsch
Keyword(s):  
Human Perception ◽  
Patient Survey ◽  
Acoustic Trauma ◽  
Sound Level ◽  
Sound Level Meter ◽  
Noise Levels ◽  
Sound Levels ◽  
Extracorporeal Lithotripsy ◽  
Level Meter ◽  
Cross Reference

AbstractPurpose:To determine the decibel sound pressure levels generated during extracorporeal lithotripsy for salivary stones, and if such lithotriptor noise levels have the potential for acoustic trauma.Patients and materials:Minilith SL-1 salivary gland lithotriptor, sound level meter; five patient survey.Methods:Decibel measurements were conducted on the lithotripter-generated sounds, using a sound level meter at specific distances from the active element. In addition, a patient survey was conducted as a cross-reference, to enable comparison of predicted results with actual human perception of sound levels.Results:Sound levels ranged between 68 and 80 dB during treatment sessions, for both the lithotriptor operator and the patient.Conclusion:During routine use, no acoustic trauma is incurred by either the lithotriptor operator or the patient.

The Accuracy of Smartphone Sound Level Meter Applications (SLMAs) in Measuring Sound Levels in Clinical Rooms

2021 ◽  
Author(s):  
Yula C. Serpanos ◽  
Janet R. Schoepflin ◽  
Steven R. Cox ◽  
Diane Davis
Keyword(s):  
Research Design ◽  
Sound Level ◽  
National Standards ◽  
Hearing Level ◽  
Sound Level Meter ◽  
Chi Square ◽  
Sound Levels ◽  
Significant Difference ◽  
Level Meter ◽  
Chi Square Analysis

Abstract Background The accuracy of smartphone sound level meter applications (SLMAs) has been investigated with varied results, based on differences in platform, device, app, available features, test stimuli, and methodology. Purpose This article determines the accuracy of smartphone SLMAs with and without calibration of external and internal microphones for measuring sound levels in clinical rooms. Research Design Quasi-experimental research design comparing the accuracy of two smartphone SLMAs with and without calibration of external and internal microphones. Data Collection and Analysis Two iOS-based smartphone SLMAs (NIOSH SLM and SPL Meter) on an iPhone 6S were used with and without calibrated external and internal microphones. Measures included: (1) white noise (WN) stimuli from 20 to 100 dB sound pressure level in a sound-treated test booth and (2) sound levels in quiet in four nonsound-treated clinical rooms and in simulated background sound conditions using music at 45, 55, and 80 dBA. Chi-square analysis was used to determine a significant difference (p ≤ 0.05) in sound measures between the SLMAs and a Type 1 SLM. Results Measures of WN signals and room sound level measures in quiet and simulated background sound conditions were significantly more accurate at levels ≥ 40 dBA using the SLMAs with calibrated external and internal microphones. However, SLMA measures with and without calibration of external and internal microphones overestimated sound levels < 40 dBA. Conclusion The SLMAs studied with calibrated external or internal microphones are able to verify the room environment for audiologic screening at 1,000, 2,000, and 4,000 Hz at 20 dB hearing level (American Academy of Audiology and American Speech-Language-Hearing Association) using supra-aural earphones (American National Standards Institute S3.1–1999 [R2018]). However, the tested SLMAs overestimated low-level sound < 40 dBA, even when the external or internal microphones were calibrated. Clinicians are advised to calibrate the microphones prior to using measurement systems involving smartphones and SLMAs to measure room sound levels and to monitor background noise levels throughout the provision of clinical services.

scholarly journals Occupational exposure of workers to noise in a carpentry

2021 ◽  
Vol 31 (Supplement_2) ◽  
Author(s):  
Ana Ferreira ◽  
Silvia Seco ◽  
João Paulo Figueiredo ◽  
António Loureiro ◽  
António Gomes
Keyword(s):  
Occupational Exposure ◽  
High Frequency ◽  
Large Scale ◽  
Preventive Measures ◽  
Sound Level ◽  
Limit Values ◽  
Professional Activities ◽  
Sound Levels ◽  
Safety And Health ◽  
Level Meter

Abstract Background Currently, we can find a more industrialized and developed society that has contributed to the large-scale expansion of sound levels. Noise is already identified as one of the main risk factors for the health of workers, due to the high frequency of workers daily exposed and risky professional activities. In this sense, it is necessary to carry out assessments of occupational noise in order to understand whether or not workers' exposure is within the limit values and what preventive measures to adopt. Methods The present study had as main objective to evaluate the occupational exposure to noise of the workers of a carpentry, located in a municipality in the Center of Portugal, and to understand its influence on their health. Measurements were performed using two devices, a Cesva dosimeter, model DC 112 and a Cesva model SC420 sound level meter. Results The results obtained demonstrated the existence of noise in some of the evaluated workstations and also the existence of some workers exposed to high levels of noise. It was also possible to observe that although all workers have hearing protection, it is not always effective. Conclusions We conclude that carpentry is a noise-producing work environment, and with the help of appropriate collective and/or individual protective equipment, it is possible to mitigate this exposure to noise, either by workers or by machines/equipment, ensuring thus the safety and health of workers.

Research: Replacing Overhead Paging with Smartphones to Reduce Hospital Noise

2020 ◽  
Vol 54 (4) ◽  
pp. 251-257
Author(s):  
Colleen A. Hughes Driscoll ◽  
Michael Cleveland ◽  
Samuel Gurmu ◽  
Sarah Crimmins ◽  
Dina El-Metwally
Keyword(s):  
Environmental Protection Agency ◽  
Average Rate ◽  
Hospital Setting ◽  
Sound Level ◽  
Recorded Sound ◽  
Sound Levels ◽  
Inpatient Settings ◽  
Level Meter ◽  
Hospital Noise ◽  
The Impact

Abstract Hospital noise is associated with adverse effects on patients and staff. Communication through overhead paging is a major contributor to hospital noise. Replacing overhead paging with smartphones through a clinical mobility platform has the potential to reduce transitory noises in the hospital setting, though this result has not been described. The current study evaluated the impact of replacing overhead paging with a smartphone-based clinical mobility platform on transitory noise levels in a labor and delivery unit. Transitory noises were defined as sound levels greater than 10 dB above baseline, as recorded by a sound level meter. Prior to smartphone implementation, 77% of all sound levels at or above 60 dB were generated by overhead paging. Overhead pages occurred at an average rate of 3.17 per hour. Following smartphone implementation, overhead pages were eliminated and transitory noises decreased by two-thirds (P &lt; 0.001). The highest recorded sound level decreased from 76.54 to 57.34 dB following implementation. The percent of sounds that exceeded the thresholds recommended by the Environmental Protection Agency and International Noise Council decreased from 31.2% to 0.2% following implementation (P &lt; 0.001). Replacement of overhead paging with a clinical mobility platform that utilized smartphones was associated with a significant reduction in transitory noise. Clinical mobility implementation, as part of a noise reduction strategy, may be effective in other inpatient settings.

Unattended Noise Monitoring: How to Fulfill IEC 61672 Sound Level Meter Standard for 0 Degree and 90 Degree Reference Directions with the Same Device

2013 ◽  
Vol 471 ◽  
pp. 130-137
Author(s):  
Patrice Pischedda ◽  
Erik Aflalo
Keyword(s):  
Leisure Activities ◽  
Maximum Level ◽  
Technical Difficulty ◽  
Sound Level ◽  
Horizontal Direction ◽  
Sound Level Meter ◽  
Multiple Sources ◽  
Noise Measurements ◽  
Noise Assessment ◽  
Level Meter

Unattended noise measurements are more and more common for noise assessment in the environment. Multiple sources are usually measured with a random position with respect to the measurement point. Noise generated by ground transportation, leisure activities, construction sites is coming from all directions, although mainly the horizontal direction. Placed vertically and configured for a reference direction of 90° from its axis, the goal is to meet the requirements of the IEC 61672 standard on sound level meters taking into account noise incidence from the horizontal direction. The main technical difficulty is the criterion for the maximum level difference allowed between two random incidence angles (directivity). The objective can be fulfilled using a cone-shaped device on top of the microphone. When measuring attended noise with the instrument in hand, the sound level meter must be pointed at the source according to standard IEC 60651. The purpose of the paper is to describe the different research & development phases to fulfill IEC 61672 sound level meter standard for 0° and 90° reference directions with the same device.

scholarly journals Noise levels of a track-laying tractor during field operations in the vineyard

2013 ◽  
Vol 44 (2s) ◽  
Author(s):  
Pietro Catania ◽  
Mariangela Vallone
Keyword(s):  
Sound Pressure ◽  
Health And Safety ◽  
Sound Level ◽  
Noise Levels ◽  
Test Conditions ◽  
Maximum Value ◽  
Sound Levels ◽  
Class 1 ◽  
Level Meter ◽  
Almost All

Noise in agriculture is one of the risk factors to be taken into account in the assessment of the health and safety of workers; in particular, it is known that the tractor is a source of high noise. The Italian Low Decree 81/2008 defined the requirements for assessing and managing noise risk identifying a number of procedures to be adopted at different noise levels to limit workers exposure. This paper concerns the analysis of the noise risk arising from the use of a tracklaying tractor during field operations carried out in the vineyard. The objective of this study was to evaluate the noise level that comes close to the ear of the operator driving the tractor measuring the values of equivalent sound level (Leq(A)) and peak sound pressure (LCpk). We considered four options related to the same tractor coupled with the following tools to perform some farming operations: rototilling, chisel plough, flail mowers and vibro farmer. We considered three test conditions: T1 in flat (slope 0%), T2 uphill and T3 downhill (both 30% slope). The instrument used for the measurements is a precision integrating portable sound level meter, class 1, model HD2110L by Delta OHM, Italy. Each survey lasted 2 minutes, with an interval of measurement equal to 0.5 s. The tests were performed in compliance with the standards ISO 9612 and ISO 9432. The results show that the measured sound levels exceed the limits allowed by the regulations in almost all the test conditions; values exceeding the threshold limit of 80 dB(A) were recorded coming up to a maximum value of 92.8 dB(A) for flail mowers in test T1. When limits imposed by the regulations are exceeded, the operator is obliged to wear the appropriate Personal Protective Equipment.

scholarly journals Effects of nightlife noise in a city center

Noise Mapping ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 228-235
Author(s):  
Gino Iannace ◽  
Amelia Trematerra ◽  
Ilaria Lombardi
Keyword(s):  
Southern Italy ◽  
Sound Level ◽  
Noise Levels ◽  
Negative Effects ◽  
City Center ◽  
Resident Population ◽  
Sound Levels ◽  
Mobile Stations ◽  
Level Meter ◽  
The City

Abstract The term Movida takes its name from the evening and night life of the city for their liveliness and animation. During the Movida, noise is one of the problems in the city centers due to the negative effects on the resident population. This paper reports the effects of noise due to the Movida phenomenon within the city center in southern Italy. Along the roads affected by the Movida phenomenon, the values of sound levels in dBA were measured both with fixed stations with a sound level meter and with mobile stations by wearing a noise dosimeter a participant of Movida. The measured noise levels are between 85 dBA to 90 dBA. The noise levels show that the Movida phenomenon generates disturbing conditions on the resident population with consequent conflict between club managers, patrons and residents.

Relation between soundscape and spatial configuration in different urban contexts

2021 ◽  
Vol 263 (5) ◽  
pp. 1405-1414
Author(s):  
Benameur Okba ◽  
Valerio Cutini ◽  
Francesco Leccese ◽  
Giacomo Salvadori ◽  
Noureddine Zemmouri
Keyword(s):  
Spatial Configuration ◽  
Space Syntax ◽  
Noise Pollution ◽  
Developed Countries ◽  
Sound Level ◽  
Sound Levels ◽  
Close Relationship ◽  
Urban Contexts ◽  
Level Meter ◽  
Global And Local

During the last decade, the problem of noise pollution has continued to increase in Europe as well as in under-developed countries. This issue is stressed in city centers, owing to the abundance of residential activities, vehicle traffic and multiple services. This study investigates the relationship between urban spatial configuration and environment soundscape in two different areas: Pisa historic center, Italy and Biskra downtown, Algeria, using the potential of Space Syntax theory in predicting noise levels distribution. For this analysis, thirty stations of measurements were held in each area during day time using a Sound Level Meter. A Noise map was modeled using the interpolation tool provided by a Geographic Information System program, while the collected data were correlated with the Angular Segment Analysis variables. The findings reveal a close relationship between the sound levels obtained and Space Syntax theory global and local indexes such as Normalized Choice and Integration, which signifies the ability of the approach in describing the sound phenomenon in different urban contexts.

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