Sound Level Research Articles

The Impact of the Fluid-Solid Coupling Behavior of Macro and Microstructures in the Spiral Cochlea on Hearing.

The cilia of the outer hair cells (OHCs) are the key microstructures involved in cochlear acoustic function, and their interactions with lymph in the cochlea involve complex, highly nonlinear, coupled motion and energy conversions, including macroscopic fluid-solid coupling. Recent optical measurements have shown that the frequency selectivity of the cochlea at high sound levels is entirely mechanical and is determined by the interactions of the hair bundles with the surrounding fluid. In this paper, an analytical mathematical model of the spiral cochlea containing macro- and micromeasurements was developed to investigate how the phonosensitive function of OHCs' motions is influenced by the macrostructural and microstructural fluid-solid coupling in the spiral cochlea. The results showed that the macrostructural and microstructural fluid-solid coupling exerted the radial forces of OHCs through the flow field, deflecting the cilia and generating frequency-selective properties of the microstructures. This finding showed that microstructural frequency selectivity arises from the radial motions of stereocilia hair bundles and enhances the hearing of sound signals at specific frequencies. It also implied that the macrostructural and microstructural fluid-solid couplings influence the OHCs' radial forces and that this is a key factor in the excitation of ion channels that enables their activity in helping the brain to detect sound.

SoundCount: Sound Counting from Raw Audio with Dyadic Decomposition Neural Network

In this paper, we study an underexplored, yet important and challenging problem: counting the number of distinct sounds in raw audio characterized by a high degree of polyphonicity. We do so by systematically proposing a novel end-to-end trainable neural network~(which we call DyDecNet, consisting of a dyadic decomposition front-end and backbone network), and quantifying the difficulty level of counting depending on sound polyphonicity. The dyadic decomposition front-end progressively decomposes the raw waveform dyadically along the frequency axis to obtain time-frequency representation in multi-stage, coarse-to-fine manner. Each intermediate waveform convolved by a parent filter is further processed by a pair of child filters that evenly split the parent filter's carried frequency response, with the higher-half child filter encoding the detail and lower-half child filter encoding the approximation. We further introduce an energy gain normalization to normalize sound loudness variance and spectrum overlap, and apply it to each intermediate parent waveform before feeding it to the two child filters. To better quantify sound counting difficulty level, we further design three polyphony-aware metrics: polyphony ratio, max polyphony and mean polyphony. We test DyDecNet on various datasets to show its superiority, and we further show dyadic decomposition network can be used as a general front-end to tackle other acoustic tasks.

Low shrinkage polyimide aerogel cross-linked with amino-functionalized hollow glass microbeads for thermal and acoustic insulation

As a nanoporous material, polyimide (PI) aerogels have excellent thermal and acoustic properties. However, their high air flow resistance is detrimental to the development of their acoustic properties. To enhance the thermal and acoustic insulation properties of PI aerogels, we have selected hollow glass microbeads (HGM) with a low thermal conductivity coefficient to be combined with the PI aerogel, leading to the fabrication of PI/HGM aerogel composite materials. In this study, there are two preprocessing methods for HGM: untreated and aminized (HGM-NH2). These were then individually combined with PI aerogel to fabricate two distinct PI/HGM composite aerogels: a physically blended variant (PIHGM) and a chemically bonded one (PHN). The thermal insulation and acoustic properties of these two composite aerogels were compared. The results show that HGM-NH2 not only functions as a cross-linking agent but also plays a key role in forming the three-dimensional network structure, which effectively reduces the shrinkage rate and density of the composite aerogel. Moreover, the thermal conductivity of PHN reached a low of 27.92 mW m⁻1 K⁻1, which is a reduction compared to PIHGM's thermal conductivity of 29.83 mW m⁻1 K⁻1. Moreover, the PHN composite aerogel with 10% HGM addition exhibited an average sound insulation level that was 120% higher than that of PIHGM. The method of incorporating pore structures with different scales also offers valuable insights for enhancing the sound insulation performance of other materials.

Development of Louvered Noise Barrier with Changeable Sound Insulation from Waste Tire Rubber and Investigation of Acoustic Properties

In line with circular economy principles, the recycling and reuse of tire rubber waste are considered highly advanced and environmentally friendly waste disposal methods. Through the repurposing of tire rubber waste, the goal is to minimize environmental impact while creating a louvered noise barrier with sound attenuation capabilities. The acoustic properties of the structure made of used tire rubber granulate are investigated in this research. Firstly, nine rubber granulate plates of different fractions, thickness, and density were produced. Two plates with the best results were selected after an impedance tube analysis of their sound absorption (α) and sound transmission loss (DTL). These plates were used as a filler in the structure of the louvers. The efficiency of the structure and its dependence on the tilting angle of the louvers and the number of plates were investigated in a semi-anechoic sound-absorbing chamber. The maximum sound level reduction observed was 17.3 dB (in the 8000 Hz frequency band), and the maximum equivalent sound level loss (LAeq) was 7.3 dBA.

Evaluation of Noise Pollution Level in Selected Sawmill Factories in Port Harcourt and Environs, Rivers State, Nigeria

Evaluation of noise pollution level has been carried out in in some selected Sawmill factories in Port Harcourt and environs using noise level and frequency meters in seven locations. The mean values of maximum and minimum sound levels in Mile2, Mile3, Marine base, Oluwood were 81.98±0.43 and 79.28±2.00, 82.450±0.66 and 80.28±0.80, 81.50±4.73 and 74.75±1.10, 81.40±0.40 and 78.03±2.02 respectively. Also the mean values of maximum and minimum sound levels at Igwuruta, Rumosi, Rumuji were found to be 82.00±0.64 and 79.40±2.00, 81.53±0.60 and 78.66±1.63, 81.78±0.40 and 77.95±1.86 respectively. The average noise equivalent (Leq) ranged from 77.20 to 82.25 dB whereas the average noise pollution level (Lnp) ranged from 96.13 to 101.23 dB. Therefore, the indication is that the Sawmill at Igwuruta has the highest average Lnp whereas Rumuosi has the least average when compared with the recommend permissible value by the Nigerian Federal Ministry of Environment (FMEnv). This study has determined the noise level generated in study area through set objectives which included but not limited to measuring the sound level, investigating noise some meters away from the source and of course comparing results with best known standards. The results therefore suggested that the noise level is high at the saw mills and the day exposure to this unwanted sound could threaten the health of the factory workers and the residents at proximity to the noise sources.

Effect of traffic speed on noise generated by vehicles motorized in front of the Karya Bhakti Pratiwi Dramaga Bogor hospital

Noise is one of the environmental health problems in big cities. The 1988 WHO report as submitted by the Indonesian Health Service (1995), states that 8% - 12% of the world's population has suffered from the effects of noise. The activity of residents of the city of Bogor a suburb of the capital city of Jakarta in Indonesia is relatively high. Along with the economic development in the city of Bogor, the number of motorized vehicles operating both private and public vehicles has also increased. The purpose of this study was to determine the average speed of motorized vehicles that pass through the Dramaga highway, especially in front of the Karya Baki Pratiwi Hospital, and also to determine the level of noise generated due to the speed of motorized vehicles. The method used in this study is a quantitative method by calculating the number of vehicles and the average speed of vehicles and data analysis. The data taken is vehicle speed data every 15 minutes and noise levels using a Sound Level Meter (SLM). In this study, three SLMs were used which would be placed at three points. The results showed that the speed of the vehicle affects the noise level which is quite significant. The results of data analysis show that the effect of speed on noise is 24%, where the equation is as follows, y=69.505 – 0.395x1 +0, 148x2 + 0.535x3. This equation means that if there is no decrease in motorcycle speed, light vehicle speed, and heavy vehicle speed, the noise level in SLM1 is 69.505 dBA. However, if there is an increase in the number of light vehicles by 0.148, a decrease in the number of motorcycles and large vehicles is obtained by 0.14, the noise level will increase by 0.395 dBA.

Assessing the influence of street canyon shape on aircraft noise: Results from measurements in courtyards near Amsterdam Schiphol Airport

Aircraft noise is a major stressor for communities in the vicinity of airports. Aircraft noise prediction models omit the built environment, based on an implicit assumption that the impact of buildings on the propagation of aircraft noise is neglectable. In this article a study is presented in which aircraft noise levels were measured near walls facing towards and away from aircraft flyovers in an urban test environment near Amsterdam Schiphol Airport. The test environment comprises three adjacent courtyards, each enclosed by stacked shipping containers. To examine the influence of street geometry on aircraft noise, specifically for slanted roofs and building insets, the shipping containers were stacked in a different pattern around each courtyard. In total, sound levels for 2383 aircraft flyovers were analysed across five months at ten microphone positions within the courtyards, for both arrivals and departures. Depending on the geometry of the courtyards, mean differences (LA,max) between facades with- and without a line of sight towards the aircraft ranged between −1,3dBA and 5,0dBA for arrivals, and 8,7dBA and 13,6dBA for departures. SEL values ranged between between −0,8dBA and 4,3dBA for arrivals, and 8,1dBA and 11,6dBA for departures. The results suggest that slanted roofs perpendicular to the flight direction deflect incident sound, substantially reducing the sounds levels inside courtyards. Contrarily, building insets at building sides facing away from the flight paths did not reduce sound levels underneath the overhangs significantly. The findings stress the importance of architectural and urban design to mitigate aircraft noise.

Effects of waste rubber particles on workability, mechanical, and sound insulation properties of recycled aggregate mortar

The influence mechanism of waste rubber particles (WRPs) on the workability, mechanical properties, and sound insulation performance of recycled aggregate sound insulation mortar (RCM) were investigated. According to the principle of volume fraction replacement of recycled fine aggregate by 0 to 50%, WRPs with a particle size of 1–4 mm were incorporated in various mixtures of RCM. Each RCM mixture was tested for workability, mechanical, and sound insulation performance. Mercury intrusion porosimetry was used to analyze the distribution of pores and their sizes inside the material, and X-ray diffraction and scanning electron microscopy were used to analyze the characteristics of the interfacial transition zones (ITZs) between the rubber particles and the cement paste. The results showed that, owing to the hydrophobicity of WRPs, greater WRPs content led to greater fluidity of the mortar mix and a smaller water retention rate. Notably, the rubber in the mortar did not contribute to the hydration reactivity of the cement paste, but it changed the crystal morphology and pore structure of ITZ hydration products. The RCM incorporating 3–10% WRPs produced the optimal pore structure through the aggregate effect, which increased its overall compactness and mechanical performance. Further increase of WRP content significantly improved the sound insulation performance while significantly reducing the strength. Moreover, there was a clear logarithmic relationship between the strength and impact sound level index. This new knowledge can be used to prepare RCM that meets the actual strength and sound insulation requirements of the floor. Thus, the resource utilization of solid waste can be expanded.

Temporary Hearing Threshold Shift in California Sea Lions (Zalophus californianus) Due to a Noise Band Centered at 32 kHz

To determine their frequency-dependent susceptibility to noise-induced temporary hearing threshold shift (TTS), two California sea lions (Zalophus californianus) were exposed for 60 min to a continuous one-sixth-octave noise band (NB) centered at 32 kHz as the fatiguing sound, at sound pressure levels of 132 to 156 dB re 1 µPa (sound exposure levels [SELs] of 168 to 192 dB re 1 µPa2s). Using a psychoacoustic technique, TTSs were quantified at the center frequency of the fatiguing sound and at half an octave and one octave above the center frequency (at 32, 44.8, and 63 kHz). When significant TTS occurred, higher SELs resulted in greater TTSs. TTSs and hearing recovery patterns were similar in both sea lions. The mean onset of TTS1-4 min (defined as 6 dB TTS) in sea lion F01 is estimated to occur after exposure to an SEL of 179 dB re 1 µPa2s (at hearing test frequency 44.8 kHz). After exposure to an SEL of 180 dB re 1 µPa2s, a mean TTS1-4 min of 6.7 dB was measured at hearing test frequency 44.8 kHz. In California sea lions, TTS onset levels are not as closely related (especially at the lower and higher frequencies) to the unmasked hearing thresholds (audiograms) as was previously assumed.

Understanding vessel noise across a network of marine protected areas

Protected areas are typically managed as a network of sites exposed to varying anthropogenic conditions. Managing these networks benefits from monitoring of conditions across sites to help prioritize coordinated efforts. Monitoring marine vessel activity and related underwater radiated noise impacts across a network of protected areas, like the U.S. National Marine Sanctuary system, helps managers ensure the quality of habitats used by a wide range of marine species. Here, we use underwater acoustic detections of vessels to quantify different characteristics of vessel noise at 25 locations within eight marine sanctuaries including the Hawaiian Archipelago and the U.S. east and west coasts. Vessel noise metrics, including temporal presence and sound levels, were paired with Automatic Identification System (AIS) vessel tracking data to derive a suite of robust vessel noise indicators for use across the network of marine protected areas. Network-wide comparisons revealed a spectrum of vessel noise conditions that closely matched AIS vessel traffic composition. Shifts in vessel noise were correlated with the decrease in vessel activity early in the COVID-19 pandemic, and vessel speed reduction management initiatives. Improving our understanding of vessel noise conditions in these protected areas can help direct opportunities for reducing vessel noise, such as establishing and maintaining noise-free periods, enhancing port efficiency, engaging with regional and international vessel quieting initiatives, and leveraging co-benefits of management actions for reducing ocean noise.

Propeller-noise reduction by microfiber coating on a blade surface

The popularity of small aerial vehicles has dramatically increased in recent years and propeller noise from such vehicles is a public health concern. Further advancement and utilization of small aerial vehicles require a substantial focus on noise reduction. Microstructures using surface and coating technology are applied in a variety of ways to address this engineering challenge. This study investigates a microfiber coating as a passive means for reducing propeller noise. The microfiber coating is comprised of a fibrous structure and has been previously shown to be a passive mean for reducing drag on a circular cylinder. To begin testing the efficacy of the microfiber coating for propeller noise reduction, microfiber-coated strips are placed at different spanwise locations on propeller blades. The sound pressure level produced by the rotating propeller is measured using a sound-level meter. The microfiber-coated propeller exhibited a lower sound pressure level than that of the uncoated propeller. At a Reynolds number of 7.4 × 104 based on the chord at the 75% spanwise station of the propeller blade, the microfiber-coated propeller achieved a noise reduction of up to 1.6 dBA compared to that of the uncoated propeller. The microfiber coating is effective in reducing broadband noise associated with the interaction of the vortex shedding associated with laminar boundary layer separation. It is found that the noise-reduction performance is a function of the spanwise location of the microfiber-coated strips.

The effect of traffic volume on the noise caused by motorized vehicles in front of Karya Bhakti Pratiwi Dramaga Hospital, Bogor

Transportation is the movement or transfer of both people and goods from a place of origin to a destination. In this movement or movement, of course, using transportation facilities in the form of vehicles which in operation cause noises such as engine sound coming out through the muffler or horn. At a certain level, these sounds can still be tolerated in the sense that the consequences they cause are not a nuisance, but at a higher level, the sound generated by these vehicles is already a nuisance or pollution, which is called noise. The activity of the population of Bogor district a suburb of the capital city of Jakarta in Indonesia is relatively high. Along with economic development in the Bogor district, the number of motorized vehicles operating both private and public vehicles has also increased. The purpose of this study was to determine the average volume of motorized vehicles that pass through the Dramaga highway, especially in front of Karya Bhakti Pratiwi Hospital, and also to determine the level of noise generated due to the volume of motorized vehicles. The method used in this study is a quantitative method by calculating the number of vehicles and the average volume of vehicles and data analysis. The data taken is vehicle volume data every 15 minutes and noise levels using a Sound Level Meter (SLM). In this study, three SLMs were used which were placed at three points. The results showed that the volume of vehicles affects the noise level quite significantly. The results of data analysis show that the effect of volume on noise is 12.6%, where the equation is as follows, y = 72.898 - 0.003 x1 + 0.220x2 - 0.054x3. This equation means that if there is no decrease in motorcycle volume, light vehicle volume, and heavy vehicle volume, the noise level in SLM 1 is 72.898 dBA. However, if there is an increase in the number of light vehicles by 0.220, it is found that the number of motorcycles and heavy vehicles is decreased by 0.22, so the noise level will increase by 0.003 dBA.

Hubungan Kualitas Aset, Rasio Kecukupan Modal, dan Efisiensi Terhadap Tingkat Kesehatan Bank

Banking institutions have influence on economic growth, so it must be ensured that banks are in a healthy condition. Lending that exceeds the maximum lending limit and only focuses on related businesses is the reason for the decline in bank health. This study aims to examine the relationship between asset quality, capital adequacy ratio, and efficiency to the soundness level of a bank. The data used in this study is secondary data in the form of financial statements of commercial banks listed on the IDX for 4 years from 2019-2022. The method used for sampling is purposive sampling method with a total population of 47 banks in the banking sector. The resulting sample is 64 data from 16 banks. The data analysis technique used in this study uses multiple linear regression techniques. The results of the regression test show that the capital adequacy ratio has no effect on the soundness of a bank, while asset quality and efficiency have a positive effect on the soundness of a bank.

Analisis Kesehatan Keuangan Perusahaan Jasa Infrastruktur Berdasarkan Surat Keputusan Menteri BUMN Nomor: KEP-100/MBU/2002 (Periode 2017-2021)

This study aims to find out about financial performance in assessing the soundness level of the financial aspects of Infrastructure Service Companies for the 2017-2021 period based on the decree of the minister of BUMN Number: KEP-100/MBU/2002 concerning the assessment of the soundness level of BUMN in this assessment using eight indicators, namely Return On Equity (ROE), Return On Investment (ROI), cash ratio, current ratio, collection periods, investory turnover, total asset turn over (TATO), and total own capital to total asset. The financial performance of infrastructure service companies for the 2017-2021 period has increased and decreased when viewed from a total score of eight financial ratio indicators during 2017-2018 infrastructure service companies have experienced increases and decreases for the level financial soundnes of infrastructure service companies are as follows in 2017 the total score 30,2 getting unhealthy predicate with category B, in 2018 a total score 21,7got an unhealthy predicate with the CCC categoty, in 2019 a totel score of 23,2 7got an unhealthy predicate with the CCC categoty, in 2020 a total score of 24 7got an unhealthy predicate with the CCC categoty, and finaly in 2021 a total score of 22,5 7got an unhealthy predicate with the CCC categoty.

Sound waves alter the viability of tobacco cells via changes in cytosolic calcium, membrane integrity, and cell wall composition.

The effect of sound waves (SWs) on plant cells can be considered as important as other mechanical stimuli like touch, wind, rain, and gravity, causing certain responses associated with the downstream signaling pathways on the whole plant. The objective of the present study was to elucidate the response of suspension-cultured tobacco cells (Nicotiana tabacum L. cv Burley 21) to SW at different intensities. The sinusoidal SW (1,000 Hz) was produced through a signal generator, amplified, and beamed to the one layer floating tobacco cells inside a soundproof chamber at intensities of 60, 75, and 90 dB at the plate level for 15, 30, 45, and 60 min. Calibration of the applied SW intensities, accuracy, and uniformity of SW was performed by a sound level meter, and the cells were treated. The effect of SW on tobacco cells was monitored by quantitation of cytosolic calcium, redox status, membrane integrity, wall components, and the activity of wall modifying enzymes. Cytosolic calcium ions increased as a function of sound intensity with a maximum level of 90 dB. Exposure to 90 dB was also accompanied by a significant increase of H2O2 and membrane lipid peroxidation rate but the reduction of total antioxidant and radical scavenging capacities. The increase of wall rigidity in these cells was attributed to an increase in wall-bound phenolic acids and lignin and the activities of phenylalanine ammonia-lyase and covalently bound peroxidase. In comparison, in 60- and 75 dB, radical scavenging capacity increased, and the activity of wall stiffening enzymes reduced, but cell viability showed no changes. The outcome of the current study reveals that the impact of SW on plant cells is started by an increase in cytosolic calcium. However, upon calcium signaling, downstream events, including alteration of H2O2 and cell redox status and the activities of wall modifying enzymes, determined the extent of SW effects on tobacco cells.

A Rapid RI-TP Model for Predicting Turbine Wake Interaction Broadband Noise

Future UHBR (Ultra-High Bypass-Ratio) engines might cause serious ‘turbine noise storms’ but, at present, turbine noise prediction capability is lacking. The large turning angle of the turbine blade is the first major factor deserving special attention. The RANS (Reynold Averaged Navier–Stokes equation)-informed (here called RI) method and LINSUB (the bound vorticity 2D model LINearized SUBsonic flow in cascade), developed to predict fan broadband noise, coupled with a two-flat-plates (here called TP) assumption for the turbine blade, is applied here, and one autonomous rapid RI-TP model for predicting turbine wake interaction broadband noise has been developed. Firstly, taking the single axial turbine test rig NPU-Turb as the object, both the experimental data and the DDES/AA (delayed Detached Eddy Simulation/Acoustic Analogy) hybrid model have been used to validate the RI-TP model. High consistency in the medium and high frequencies among the three designed and off-designed rotation speeds indicates that the RI-TP model has the ability to predict turbine broadband noise rapidly. And compared with the original RANS-informed method, with one thin-flat-plate assumption on the blade, the RI-TP model can enhance the PWL (sound power level) in almost the whole spectral range below 10 KHz, which, in turn, is closer to the experimental data and the DDES/AA prediction results. The PWL trend with a ‘dividing point’ position is also studied. The spectrum would move up or down if the location is away from true value. In addition, the extraction location for turbulence as an input for the RI-TP model is negligible. In the future, multi-stage characteristics and the blade thickness effect should be further considered when predicting turbine noise.

A thin-walled cavity structure with double-layer tapered scatterer locally resonant metamaterial plates for extreme low-frequency attenuation

Locally resonant acoustic metamaterials (LRAMs) are effective spatial frequency filters due to their local resonance system. However, they own narrow stopbands, charge additional weight on the primary system, and operate only at the adjusted frequency range. In this paper, a novel dual-target LRAM is proposed based on coupling the cavity and convex mechanisms, utilizing the benefits of both sound-barrier and sound-absorbing types of acoustic metamaterials. A combination of the cavity and convex structures is presented and investigated for the first time, which exploits both the reflection and absorption theories simultaneously to improve the sound attenuation performance of acoustic metamaterials. By arranging two-layer finite periodic of 5×5 proposed convex unit cells along x and y directions and separating them by an air cavity, a supercell named hybrid locally resonant acoustic metamaterials (HLRAM) baffle is designed. The band structures, transmission spectrum, and displacement vector fields are calculated employing the finite element method (FEM). In addition, vibration modes at the edges of stopbands are computed and carefully analyzed to determine the formation mechanism, mechanics/dynamic response, and dispersion features of stopbands. Meanwhile, sensitivity analyses have been conducted on the model to investigate the influence of material and geometry parameters on dispersion characteristics. Equivalent spring-mass analytic models are used to direct the modifications of structure and the adjustment of structural and material parameters in order to achieve a wide stopband with a low opening frequency. Thereby, the effective stiffness and mass values influencing the starting and cutoff frequencies are adjusted in a desirable manner. The results show that the structure can generate a wide stopband that covers the frequency range of 64.9-805.6Hz, allowing the structure to block incoming acoustic waves with 35.42dB root mean square of noise attenuation (RMSNA) the given frequency range (0-1kHz). This study indicates that the HLRAM has a preponderance among conventional techniques as we can manipulate dispersion characteristics and the sound transmission loss (STL) based on the desired sound reduction level and shift stopbands to the intended frequency range. This can be achieved by altering cavity size, material, or geometry parameters.

Study on Temporary Unloading for Chatter Vibration Suppression Using Fixed Superabrasive Polishing Stone with Five-Joint Closed-Link Small Robot and Voice Coil Motor Thrust Control

In this study, an existing superfinishing method used for polishing glass surfaces was refined using a five-joint closed-link compact robot with fixed abrasive grains. In previous studies, a voice coil motor was used to control the constant-pressure pressing force while maintaining the polishing force for a relatively short period. However, maintaining the polishing force for long periods is imperative for achieving a high-quality polished surface. Thus, in this study, a strain gauge load cell was adopted in addition to a conventional piezoelectric force sensor to maintain the polishing force for a long period. First, the amounts of DC drift of the piezoelectric force sensor and strain gauge type load cell were compared to confirm the necessity of signal processing as well as the compatibility of long-term force measurement and high-frequency vibration measurement by application. Further, a method was proposed in which the change in the pressing force was recorded from the connected sensor; when the pressing force fluctuated, chatter vibrations were determined to occur, and the pressing force was temporarily set to 0 N. This method could obtain a better polished surface than the proportional-integral-differential (PID) control, which simply controls the pressing force at a constant value. Finally, chatter vibrations could be determined by detecting high-frequency sounds using a sound level meter. Notably, a finely polished surface could be obtained.

Investigation of whistle noise impacting a residential subdivision

There have been complaints from residences within a residential subdivision in New Tecumseth, Ontario, of train noise from the Canadian Pacific Railway (CPR) line that passes directly east of the development. The complaints relate to sound levels experienced within the dwellings during train pass-bys, most notably from the use of whistles at the grade level crossing southeast of the site. Sound level measurements were completed to quantify the indoor and outdoor sound levels at several dwellings closest to the rail line. The measured sound levels were compared to predictions made using the Ministry of the Environment, Conservation and Parks (MECP) noise model Sound from Trains Environmental Analysis Method (STEAM). This investigation discusses shortfalls in STEAM, which resulted in the sound levels (from whistle noise) being under predicted at the dwellings. The study also compares the sound levels predicted using the Federal Railway Administration (FRA) horn noise model to those measured on site and predicted using STEAM.

Taipei performing arts center surrounding soundscape study and its application

Taipei Performing Arts Center designed by architect Rem Koolhaas and his firm OMA, features three theaters stacked vertically. The cube-shaped structure features a distinctive geometric facade, serving as the seating areas for the three main theaters. These giant facades, due to their sloped seating surfaces, could also function as significant sound-reflecting and focusing panels, potentially amplifying the nearby MRT and traffic noise. The project was strategically located near Shihlin Nightmarket for the area's cultural and economic growth. ISO-12913 soundscape study method is used to document essential sound sources, paths, and levels. The average sound pressure level of 67.4 decibels around the building provides an indication of the ambient noise in the immediate vicinity. While the acoustic comfort level in the plaza beneath the prominent facades may not be optimal, it is crucial to acknowledge their dual role as guiding individuals into the performance hall and serving as a buffer between external traffic and internal events. In addition to evaluating the impact of building mass and envelope design decisions on sound levels, this study uncovers a noteworthy finding related to urbanized traffic beeping. The observed and mapped patterns of local traffic sounds reveal unique cultural messages embedded in the auditory landscape.