Large aperture microphone array measurement at operating airport for sound source model creation of J-FRAIN

Maximum sound pressure levels are commonly used for environmental noise and building acoustics measurements. This paper investigates the signal processing errors due to Fast or Slow time-weighting detectors when combined with octave band filters, one-third octave band filters or an A-weighting filter. For 6th order Butterworth CPB filters the inherent time delay caused by the phase response of filters is quantified using three different approaches to establish the following rules-of-thumb: (1) time-to-gradient/amplitude matching occurs when Bt≈1, (2) time-to-peak matching occurs when Bt≈2 and (3) time-to-settle matching occurs when Bt≈4 for octave band filters, and when Bt≈3 for one-third octave band filters. Four different commercially-available sound level meters are used to quantify the variation in measured maximum levels using tone bursts, half-sine pulses, ramped noise and recorded transients. Tone bursts indicate that Slow time-weighting is inappropriate for maximum level measurements due to the large bias error. The results also show that there is more variation between sound level meters when considering Fast time-weighted maximum levels in octave bands or one-third octave bands than with A-weighted levels. To reduce the variation between measurements with different sound level meters, it is proposed that limits could be prescribed on the phase response for CPB filters and A-weighting filters.

This Recommendation deals with sound level meters, i.e. instruments for the measurement of frequency and time weighted sound pressure levels. It contains an appropriate test scheme for pattern evaluation and verification and a test report format for pattern evaluation.

A methodological development is proposed to compare the results of measurements of the equivalent level of noise exposure (ambient sound) and SEL in urban areas near traffic routes obtained in the conventional way by using a fixed-point sound level meter and mobile noise dosimeters with respect to the location of the sound level meter. Class I calibrated equipment is used for the sound level meter and Class II for the dosimeter. Comparisons are made by maintaining a fixed point location for the sound level meter and using 1 dosimeter for measurements in different media moving with reference to the fixed point. The investigation is ongoing. To simulate the measured scenarios a mathematical model, from the Department of Mechanical and Energy Engineering of the Miguel Hernandez University of Elche (Spain), is used to compare measured results against model results. The field values are used to calibrate the model validating it for use when it is necessary to have exposure values at different heights. The first results show an appreciable difference between noise exposure results in the conventional way, for different environments in urban areas close to traffic routes, with the highest incidence on pedestrians.

Intensive care units (ICUs) may disrupt sleep. Quantitative ICU studies of concurrent and continuous sound and light levels and timings remain sparse in part due to the lack of ICU equipment that monitors sound and light. Here, we describe sound and light levels across three adult ICUs in a large urban United States tertiary care hospital using a novel sensor. The novel sound and light sensor is composed of a Gravity Sound Level Meter for sound level measurements and an Adafruit TSL2561 digital luminosity sensor for light levels. Sound and light levels were continuously monitored in the room of 136 patients (mean age = 67.0 (8.7) years, 44.9% female) enrolled in the Investigation of Sleep in the Intensive Care Unit study (ICU-SLEEP; Clinicaltrials.gov: #NCT03355053), at the Massachusetts General Hospital. The hours of available sound and light data ranged from 24.0 to 72.2 hours. Average sound and light levels oscillated throughout the day and night. On average, the loudest hour was 17:00 and the quietest hour was 02:00. Average light levels were brightest at 09:00 and dimmest at 04:00. For all participants, average nightly sound levels exceeded the WHO guideline of < 35 decibels. Similarly, mean nightly light levels varied across participants (minimum: 1.00 lux, maximum: 577.05 lux). Sound and light events were more frequent between 08:00 and 20:00 than between 20:00 and 08:00 and were largely similar on weekdays and weekend days. Peaks in distinct alarm frequencies (Alarm 1) occurred at 01:00, 06:00, and at 20:00. Alarms at other frequencies (Alarm 2) were relatively consistent throughout the day and night, with a small peak at 20:00. In conclusion, we present a sound and light data collection method and results from a cohort of critically ill patients, demonstrating excess sound and light levels across multiple ICUs in a large tertiary care hospital in the United States. ClinicalTrials.gov, #NCT03355053. Registered 28 November 2017, https://clinicaltrials.gov/ct2/show/NCT03355053.

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. Minilith SL-1 salivary gland lithotriptor, sound level meter; five patient survey. 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. Sound levels ranged between 68 and 80 dB during treatment sessions, for both the lithotriptor operator and the patient. During routine use, no acoustic trauma is incurred by either the lithotriptor operator or the patient.

As a part of the ongoing work on the new standard IEC 61672 Electroacoustics–Sound level meters, the TC29 WG4 working group is writing the specifications for the periodic verification of sound level meters. Recent investigations of historical data have shown that the frequency response for the microphone is the most likely cause for the rejection of a sound level meter under test. It is therefore very important to measure the frequency response of the sound level meter with acoustical input signals. In order to keep the cost of the test down, it is essential to be able to choose a fast and sufficiently accurate method. In this paper some of the possible measurement methods such as free-field comparison, electrostatic actuator, multifrequency calibrator, and comparison coupler are described. The focus is on their advantages, drawbacks, and their associated uncertainties.

Background & Aims: Noise exposure can impact nurses' performance and may result in disruptions to their tasks.This study aimed to examine the correlation between the average equivalent sound level and the occurrence of medication errors. Materials & Methods:This cross-sectional study involved 150 nurses in Iran in 2020.First, two medical and two surgical wards were randomly selected using a coin toss method.Second, the nurses who worked in those wards were sampled using the convenience method.Nurses' medication errors were assessed using a questionnaire.A sound level meter was used to measure the sound level in decibel.Data were analyzed using analytical tests, including Kruskal-Wallis, Spearman correlation coefficient, and Poisson model. Results:The mean sound equivalent level in the cardio-respiratory internal ward (58.94 ± 1.88) was higher than the same level in the other internal and surgical wards (p < 0.001).An increase in the mean sound equivalent level in the wards was accompanied by an increase in the mean number of medication errors among unmarried individuals (e 0.22 = 1.25), which was 1.25 times more than the errors made by married individuals.Finally, an increase in age and the mean sound equivalent level resulted in the occurrence of medication errors (p < 0.002). Conclusion:The results showed that there was no relationship between the sound pressure level and nurses' medication errors in the research environment.Therefore, it is necessary to conduct more studies to investigate the factors that increase the incidence of medication errors.

Mobile sound level applications have been proposed as potential adjuncts for conventional sound level meters (SLM) in noise measurement. However, their performance remains uncertain in the manufacturing industry setting. This study was aimed to determine the validity, reliability, and agreement of the NIOSH SLM app in measuring noise in the manufacturing industry with reference to conventional SLM. A total of 93 samples were collected from five machineries. An iPhone 12 Pro and an iPhone 12 mini, each installed with the latest version of NIOSH SLM app, were tested against the conventional SLM (as gold standard). Three noise parameters, namely the average noise level (i.e., LAeq), maximum sound level (i.e., LMax) and 8-hour time-weighted average (i.e., TWA-8 h) were measured by all devices. Concurrent validity was assessed using Pearson’s correlation coefficient while two-way mixed effects intraclass correlation coefficient (ICC 3,1) was used to assess the intra-rater reliability. The agreement in the noise parameters measured was assessed using the Bland-Altman plot. The NIOSH SLM app demonstrated high concurrent validity, as measured by Pearson’s correlation (p < 0.001) and moderate-to-good reliability, as measured by ICC 3,1 (p < 0.001) in all three noise parameters measured. The LAeq and TWA-8 h measured by the NIOSH SLM app were in agreement with the conventional SLM, with the exception of LMax. The NIOSH SLM app is valid and reliable in measuring noise when compared to conventional SLM. Two out of three noise parameters measured by NIOSH SLM app were agreeable to that measured by the conventional SLM.

Excessive environmental noise and poor air quality can be adverse to human health, living comfort and the environment itself. Measurement of sound pressure levels and air quality in critical areas including libraries, campus areas, public parks and hospitals thus becomes necessary to monitor and mitigate existing noise levels. In a university environment, student activities will be less disrupted if the locations of the activities are sufficiently away from noise sources. The present study is intended to measure sound levels and air quality around the Engineering Complex, Universiti Teknologi Mara, Shah Alam. The measured data is compared with to acceptable sound pressure levels and air quality index specified by the Department of Environment (DOE), Malaysia. Sound pressure levels are measured using the Castle Sound Level Meter Type 6224 and air quality measurement was done by using the BW Gas Alert MicroClip XT device. Both measurements were conducted at five selected stations around the Engineering Complex for three times each weekday for five weeks. Results obtained indicated that sound levels at some locations and time zones are above the thresholds recommended by the DOE. The air quality is acceptable in most locations except the vicinity of a bus stop. With the growing number of students in the university and other factors like construction and redevelopment of existing roads, a continuously increasing noise situations and air pollution proportional to the traffic flow is inevitable.

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 &amp; development phases to fulfill IEC 61672 sound level meter standard for 0° and 90° reference directions with the same device.

It has been designed a sound pressure level detection for response of tympanic membrane based on optical fiber with extrinsic method. The fiber optic sensor is used to measure the sound pressure level by utilizing the output voltage change. The sound level pressure values obtained are displayed on OLED display. Testing tools with sound level meter comparison tool to test sound pressure level in poly ENT patients. The test results show that at sound pressure level measurement with frequency 200 Hz to 300 Hz, the average accuracy is 93.42% for right ear, at the same time for left ear the average accuracy is 94.58%. The test of compliance measurement the average accuracy is 77.97% for the right ear, at the same time for the left ear the average accuracy is 70.74%. The testing of the appliance to patient in Andalas University hospital poly ENT were detect the values of sound pressure level 60 dB to 65 dB.Â

Accuracy in the measurement of sound levels in situ with sound level meters

The measurements necessary for the determination of the random incidence responses of microphones and sound level meters were made from 500–20 000 Hz in an anechoic chamber using both single-frequency tenes and 1/3-octave bands of noise. The random incidence responses were computed from these data using formulas given in the relevant IEC and ANSI standards documents and according to a Gaussian-type numerical integration formula. This Gaussian formula appears to introduce less numerical error due to the approximation procedure used to compute the random incidence response than either the IEC or ANSI formulas. The random incidence responses of the microphones and sound level meters tested in the anechoic room were also measured in two reverberation rooms using both discrete sampling of the reverberant field and two types of continuous sampling: linear and circular. The results from the various methods and procedures are compared to the exact values (determined by a numerical procedure that used at least 30 points) and the minimum number of points (angles) necessary to achieve a prescribed level of accuracy in the random incidence responses are determined.

Noise pollution can come from noise generated by nature, one of which is noise from river flows. Therefore, the aim of this research was to determine whether the sound intensity level of the river flow is still below the threshold value or whether it has disturbed human hearing. The research method used was to measure the sound intensity level of the Cinangneng-Bogor river flow by using a sound level meter application. Measurement of the sound intensity level was carried out at 5 measurement points, namely in the middle of the river flow, on the river bank, at a distance of 5 m, 10 m and 15 m from the river bank to the land. Each measurement was carried out for 120 seconds. The results showed that the sound intensity level of the Cinangneng-Bogor river flow at several measurement points had different values, namely from the middle of the river to away from the river the values were 96.34 DbA, 92.31 DbA, 78.93 DbA, 76.58 DbA and 76.32 DbA. In conclusion, the further away from the noise source, the lower the noise level. The sound intensity in the middle and on the river bank was above the threshold value.

Menurut Menteri Agama sesuai dengan Surat Edaran Menteri Agama Republik Indonesia tentang Pedoman Penggunaan Pengeras Suara di Masjid dan Musala, penggunaan pengeras suara di masjid dan musala merupakan kebutuhan bagi umat Islam sebagai salah satu media syiar Islam di tengah masyarakat. Pada saat yang bersamaan, masyarakat Indonesia juga beragam, baik agama, keyakinan, latar belakang, dan lainnya. Oleh karena itu, diperlukan upaya untuk merawat persaudaraan dan harmoni sosial. Merujuk kepada poin C.2.c tentang Ketentuan Pemasangan dan Penggunaan Pengeras Suara, volume pengeras suara diatur sesuai dengan kebutuhan, dan paling besar 100 dB (seratus desibel). Dari ketentuan tersebut, Prodi Sarjana Terapan Teknik Telekomunikasi akan menerapkan sistem pengukur level pengeras suara masjid dan musala sebagai standardisasi dan prosedur operasi khusus (SOP) yang dapat digunakan dengan mudah oleh masjid dan musala yang ada di seluruh Indonesia. Penggunaan alat pengukur level suara yang ada di pasar atau yang dapat disebut sebagai digital sound level meter, akan digunakan untuk mempermudah operasional dan ketersediaan alat. Dengan adanya pengabdian masyarakat ini, diharapkan alat pengukur suara takmir masjid dan masyarakat dapat menggunakan pengeras suara masjid sesuai Surat Edaran Menteri Agama No SE. 05 Tahun 2022.