scholarly journals Educational Implementation of a Sound Level Meter in the LabVIEW Environment

2013 ◽  
Vol 38 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Robert Baranski ◽  
Grazyna Wszołek
Keyword(s):  
Acoustic Signal ◽  
Theoretical Background ◽  
Sound Level ◽  
Practical Training ◽  
Acoustic Measurements ◽  
Virtual Device ◽  
Team Activity ◽  
Level Meter ◽  
The Moment ◽  
Individual Contact

Abstract As a consequence of recent implementations of EU Directives related to noise protection more and more students of various AGH-UST programs are introduced to the basics of acoustic measurements. Students at various levels of theoretical background in the field of acoustic measurements are offered practical training in measurements using digital sound analyzers. The situation would be optimal if each student could have a device at his/her own disposal. Unfortunately, such a situation is not possible at the moment because of various reasons. With the above problem in mind, a dedicated software package has been developed, implemented in the LabVIEW environment, which allows detailed studies of problems related to the acoustic signal measurement using sound level meters, as well as tasks in spectral analysis (1/1 and 1/3 band filters) and narrow-band (FFT) analysis. With such organization during the introductory laboratory classes each student is offered a direct individual contact with a virtual device that is properly pre-programmed for realization of a well-constructed learning process. It definitely facilitates understanding of the essence of acoustic signal measurements and provides a good basis for further laboratory work carried out as a team-activity.

scholarly journals Research for the Presence of Unmanned Aerial Vehicle inside Closed Environments with Acoustic Measurements

Buildings ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 96
Author(s):  
Giuseppe Ciaburro ◽  
Gino Iannace ◽  
Amelia Trematerra
Keyword(s):  
Unmanned Aerial Vehicle ◽  
Sound Level ◽  
Anthropogenic Noise ◽  
Acoustic Measurements ◽  
Noise Emission ◽  
Tonal Component ◽  
Aerial Vehicle ◽  
Level Meter ◽  
Closed Environment ◽  
Typical Frequency

Small UAVs (unmanned aerial vehicle) can be used in many sectors such as the acquisition of images or the transport of objects. Small UAVs have also been used for terrorist activities or to disturb the flight of airplanes. Due to the small size and the presence of only rotating parts, drones escape traditional controls and therefore represent a danger. This paper reports a methodology for identifying the presence of small UAVs inside a closed environment by measuring the noise emitted during the flight. Acoustic measurements of the noise emitted by a drone inside a large environment (12.0 × 30.0 × 12.0 m) were performed. The noise was measured with a sound level meter placed at different distances (5, 10, and 15 m), to characterize the noise in the absence of anthropic noise. In this configuration, a typical tonal component of drone noise is highlighted at the frequency of one-third of an octave at 5000 Hz due to the rotation of the blades. This component is also present 15 m away from the source point. Subsequent measurements were performed by introducing into the environment, through a loudspeaker, the anthropogenic noise produced by the buzz of people and background music. It is possible to distinguish the typical tonal component of UAV noise at the frequency of 5000 Hz even when the level of recording of anthropogenic noise emitted by the loudspeaker is at the maximum power tested. It is therefore possible to search for the presence of small UAVs inside a specific closed environment with only acoustic measurements, paying attention to the typical frequency of noise emission equal to 5000 Hz.

Measurement of Noise inside the Compartment and Vibration on both Sides of Elastomeric Powertrain Mounts of Passenger Car

2013 ◽  
Vol 471 ◽  
pp. 59-63
Author(s):  
Mohd Noor Arib Rejab ◽  
Roslan Abd Rahman ◽  
Raja Ishak Raja Hamzah ◽  
Jawaid Iqbal Inayat Hussain ◽  
Nazirah Ahmad ◽  
...  
Keyword(s):  
Fast Response ◽  
Sound Level ◽  
Measurement Noise ◽  
The Other ◽  
Vibration Level ◽  
Test Conditions ◽  
Exhaust Noise ◽  
Run Up ◽  
Level Meter ◽  
High Level

This paper presents an evaluation on elastomeric mount used to isolate vibration from powertrain to chassis or structure vehicle. The assessments started with measurement of noise inside compartment, and exhaust noise. This is followed by the measurement of vibration on both sides of elastomeric mounts. The noise in the compartment and exhaust noise is measured according to BS 6086: 1981 and BS ISO 5130: 2007. The noise in the compartment and vibration is tested in three conditions. Firstly, engine is run-up with load (driving at second gear); secondly, without load; and thirdly, without load but hanging. A microphone is fixed at the ear of the mannequin. The fast response and A weighting sound level meter were used for measurement noise in the compartment and exhaust noise. The vibration is measured in terms of acceleration on both sides of each elastomeric powertrain mounts. Two accelerometer transducers are fixed on both sides of powertrain elastomeric mounts. One side was identified as a source of vibration and the other as receiver of vibrations. The results showed that the pattern of overall vibration level on source and receiver increased from 1050 RPM (idling) to 4000 RPM on all test conditions. Vibration transmitted to chassis or receiver structure was analyzed using transmissibility concept. By evaluating test condition of engine run-up without load, informed that the front and rear mounts showed a high level transmissibility contributing to structure-borne noise.

Testing of Sonic-Absorbent Panels’ Behavior in Open-Air Environment

2012 ◽  
Author(s):  
Petru A. Pop ◽  
Patricia A. Ungur ◽  
Liviu Lazar ◽  
Mircea Gordan ◽  
Florin M. Marcu
Keyword(s):  
High Frequency ◽  
Noise Pollution ◽  
Sound Level ◽  
Sound Level Meter ◽  
Data Logger ◽  
Public Buildings ◽  
Gypsum Plaster ◽  
Level Meter ◽  
And Control

One wildly used method to reduce and control the noise pollution in green city’s buildings is using sonic-absorbent panels. Their applications can be multiple, such as the insulation of buildings, acoustic barriers and fences along the highway or in front of supermarkets, hospitals and other public buildings. This paper presents a method for testing the behavior of sonic-absorbent panels in open-air environment. The work represents a carrying on of previous research about absorbent materials from gypsum family, tested in lab conditions. The experiment setup used a dynamic installation and as a sample a stand formed by six sonic-absorbent panels from special modeling alpha-gypsum plaster. This installation has been composed of two loudspeakers for emitting the sound at a well-defined frequency by the first laptop, the microphone for detecting and transmitting the signal to the second laptop for analyzing and processing the data. All operations were performed using MATLAB Programs, while a Data Logger Sound Level Meter type CENTER 332 was put on near the microphone to compare both results. The first experiment of acoustic stand has been realized by setting up the installation at a frequency from 50 Hz to 1250 Hz and altering the distance between loudspeakers and stand at 0.5m to 1m and 1.5m, respectively. The second experiment kept the same test’s conditions, while two and three layers of sonic-absorbent panels formed the stand, respectively, but at same distance from source of 0.5 m. In both tests, the results underlined the good sonic-absorbent properties of these panels, especially at medium and high frequency, which can recommend using the panels for multiple outside applications.

Pemetaan Dan Perhitungan Pemaparan Tingkat Kebisingan Pada Industri Pengolahan Kayu Di Kecamatan Siak, Provinsi Riau

2021 ◽  
Vol 6 (2) ◽  
pp. 68-76
Author(s):  
Aryo Sasmita ◽  
Muhammad Reza ◽  
Rodesia Mustika Rozi
Keyword(s):  
Sound Level ◽  
Sound Level Meter ◽  
Noise Mapping ◽  
Level Meter

Dalam kegiatan operasionalnya CV. X yang bergerak pada pengolahan kayu, berpotensi menimbulkan kebisingan yang berasal dari mesin-mesin yang digunakan dalam proses produksi pallet. Kebisingan di perusahaan ini dapat berpengaruh terhadap kesehatan dan kenyamanan pekerja. Penelitian ini bertujuan untuk mengetahui intensitas kebisingan yang dihasilkan oleh mesin produksi, lama waktu pemaparan, pemetaan kebisingan dan upaya pengendalian kebisingan. Metode pengukuran kebisingan mengacu pada metode noise mapping dan alat yang digunakan adalah Sound Level Meter. Data yang diperoleh kemudian diolah menjadi peta kontur dengan variasi warna biru, hijau, kuning, ungu dan merah. Hasil penelitian menunjukkan tingkat kebisingan tertinggi sebesar 99,4 dB dan tingkat kebisingan terendah sebesar 67,3 dB. Berdasarkan hasil perhitungan menggunakan persamaan NIOSH dari 128 titik pengukuran metode noise mapping terdapat 38 titik dengan tingkat kebisingan >85 dB yang menunjukkan waktu pemaparan di atas standar yang sudah direkomendasikan NIOSH. Tingkat kebisingan tertinggi sebesar 99,4 dB dengan lama pemaparan selama 0,3 jam dan tingkat kebisingan terendah sebesar 67,3 dB dengan lama pemaparan selama 475 jam. Upaya pengendalian yang dapat dilakukan untuk mengurangi kebisingan seperti pengendalian dari sumber, jalur transmisi, dan penerima.

A Sound Level Meter featured with automatic estimation of the measurement uncertainty

Measurement ◽  
2021 ◽  
pp. 110409
Author(s):  
Marco Carratù ◽  
Consolatina Liguori ◽  
Vincenzo Paciello ◽  
Antonio Pietrosanto ◽  
Domenico Russo ◽  
...  
Keyword(s):  
Measurement Uncertainty ◽  
Sound Level ◽  
Sound Level Meter ◽  
Automatic Estimation ◽  
Level Meter

scholarly journals Investigation of Flow Behavior around Corotating Blades in a Double-Spindle Lawn Mower Deck

2005 ◽  
Vol 2005 (1) ◽  
pp. 77-89 ◽  
Author(s):  
W. Chon ◽  
R. S. Amano
Keyword(s):  
Flow Pattern ◽  
High Speed ◽  
Flow Behavior ◽  
Flow Analysis ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Video Camera ◽  
Sound Level ◽  
Lawn Mower ◽  
Level Meter

When the airflow patterns inside a lawn mower deck are understood, the deck can be redesigned to be efficient and have an increased cutting ability. To learn more, a combination of computational and experimental studies was performed to investigate the effects of blade and housing designs on a flow pattern inside a1.1mwide corotating double-spindle lawn mower deck with side discharge. For the experimental portion of the study, air velocities inside the deck were measured using a laser Doppler velocimetry (LDV) system. A high-speed video camera was used to observe the flow pattern. Furthermore, noise levels were measured using a sound level meter. For the computational fluid dynamics (CFD) work, several arbitrary radial sections of a two-dimensional blade were selected to study flow computations. A three-dimensional, full deck model was also developed for realistic flow analysis. The computational results were then compared with the experimental results.

Recognition for Spindle Speeds of Drill Press Based on Sound Signals Produced from Drilling

2008 ◽  
Vol 375-376 ◽  
pp. 535-538
Author(s):  
Xiang Feng Li ◽  
Gen Lian Yang ◽  
Dun Wen Zuo
Keyword(s):  
Wavelet Packet ◽  
Sound Level ◽  
Effective Characteristics ◽  
Frequency Bands ◽  
Training Samples ◽  
Bp Networks ◽  
Training Error ◽  
Effective Network ◽  
Level Meter ◽  
Drill Press

Effects of running state and spindle speeds on the sound signals produced from a drill press are investigated. And the obtained sound signals by using of a sound level meter are analyzed in both time domain and frequency domain. It is evident that there is more high frequency energy for drilling sound signals with load than without load. And spindle speeds still affect their energy distribution of drilling sound signals. Using wavelet decomposition and wavelet packet decomposition, drilling sound signals are decomposed into a number of frequency bands. And energy percentages of the divided frequency bands are extracted to be the effective characteristics to recognize spindle speeds. Meanwhile, training error of different BP networks is compared to obtain the effective network for recognition spindle speeds. By using of the obtained network structure named 16-30-5, the study rate for training samples and the recognize rate for testing samples are all above 95%.

S254 – Bone Conduction Noise Exposure via Ventilators in the NICU

2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P160-P160
Author(s):  
Angela P Black ◽  
James D Sidman
Keyword(s):  
Ambient Noise ◽  
Noise Exposure ◽  
Bone Conduction ◽  
Sound Level ◽  
Noise Levels ◽  
High Noise ◽  
Endotracheal Tubes ◽  
Level Meter ◽  
Hearing Damage ◽  
Air Conduction

Objectives To demonstrate that neonatal ventilators produce high noise levels through bone conduction (BC) via endotracheal tubes, as well as air conduction (AC) from ambient noise. Methods A sound level meter was used to measure the noise levels 4 feet from the ventilator and in direct contact at the end of a balloon attached to the ETT to simulate the noise presented to the infant. 3 commonly used neonatal ventilators (Sensormedics 3100A, VIP Bird and Bunnell Jet) were examined. Results Noise levels were significantly higher (6 – 14 dB) at the end of the ETT than 4 ft from the ventilator for all ventilators studied. Conclusions Previous studies have shown high ambient noise levels in NICUs, but have failed to address the actual noise presented to the infant. ETT transmission of noise as a direct bone stimulus through the skull has been overlooked. This study has shown that high noise intensities are being presented not only as AC, but as BC to the infants though the ETT. This study demonstrates, therefore, that ear protection alone will not save these at-risk infants from hearing damage. More must be done to decrease noise exposure and develop quieter machines.

Noise Exposure Associated With Hearing Aid Use in Industry

1996 ◽  
Vol 39 (2) ◽  
pp. 251-260 ◽  
Author(s):  
Thomas G. Dolan ◽  
James F. Maurer
Keyword(s):  
Hearing Aids ◽  
Noise Exposure ◽  
Hearing Aid ◽  
Sound Field ◽  
High Gain ◽  
Sound Level ◽  
Weighted Averages ◽  
Hearing Aid Use ◽  
Listening Environments ◽  
Level Meter

Although noise may be innocuous in many vocational environments, there is a growing concern in industry that it can reach hazardous levels when amplified by hearing aids. This study examined the daily noise exposures associated with hearing aid use in industry. This was done by both laboratory and site measurements in which hearing aids were coupled to the microphone of an integrating sound level meter or dosimeter. The former method involved the use of recorded railroad and manufacturing noise and a Bruel and Kjaer 4128 Head and Torso simulator. In the latter procedure, a worker wore one of three hearing aids coupled to a dosimeter during 8-hour shifts in a manufacturing plant. Both methods demonstrated that even when amplified by mild-gain hearing aids, noise exposures rose from time-weighted averages near 80 dBA to well above the OSHA maximum of 90 dBA. The OSHA maximum was also exceeded when moderate and high gain instruments were worn in non-occupational listening environments. The results suggest that current OSHA regulations that limit noise exposure in sound field are inappropriate for hearing aid users.

Sign in / Sign up

Export Citation Format

Share Document