Octave Frequency Bands Research Articles

Feasibility of hearing aid gain self-adjustment using speech recognition.

Personal hearing devices, such as hearing aids, may be fine-tuned by allowing the users to conduct self-adjustment. Two self-adjustment procedures were developed to collect the listener preferred gains in six octave-frequency bands from 0.25 kHz to 8 kHz. These procedures were designed to allow rapid exploration of a multi-dimensional parameter space using a simple, one-dimensional user control interface (i.e., a programmable knob). The two procedures differ in whether the user interface controls the gains in all frequency bands simultaneously (Procedure A) or only the gain in one frequency band (Procedure B) on a given trial. Monte-Carlo simulations suggested that for both procedures the gain preference identified by simulated listeners rapidly converged to the ground-truth preferred gain profile over the first 20 trials. Initial behavioral evaluations of the self-adjustment procedures, in terms of test-retest reliability, were conducted using 20 young, normal-hearing listeners. Each estimate of the preferred gain profile took less than 20 minutes. The deviation between two separate estimates of the preferred gain profile, conducted at least a week apart, was about 10 dB ~ 15 dB.

On the performance investigation of distinct algorithms for room acoustics simulation

The purpose of this research is to investigate the accuracy provided by different algorithms for room acoustics simulation. Three software packages are used to simulate the monaural room impulse responses of a medium-sized concert hall. All algorithms deal with geometrical acoustics but with distinct implementations. The simulated room is one of those adopted as a benchmark for the first round robin on room acoustical simulation and auralization, the last international inter-comparison, for which the geometrical and acoustic data were carefully measured. The main novelty is the inclusion of the software RAIOS, which participated in the round robin but did not finish the simulations in time to be included in the publication. Four acoustical parameters, namely the reverberation time, the early decay time, the clarity factor for music, and the definition for speech, are computed for ten source-receiver pairs at octave band frequencies from 125 Hz to 8 kHz. The results obtained by the three software are then compared with the measured data for all source-receiver positions and frequency bands. The relative mean errors to the just noticeable difference (JND) are also computed. The main findings are that there are deviations relative to the measured results for all software, with some of the parameters being better evaluated than others are. Preliminary insights into the advantages and limitations of the software packages with respect to the monaural impulse response are also given.

Electric vehicle additive sounds: Detection results from an outdoor test for sixteen participants

Electric vehicles are significantly quieter than standard internal combustion engine vehicles. Although this is a benefit to the acoustic soundscape, it presents a safety concern, particularly to the vision impaired. Because of this, governments around the world have mandated that artificial sounds be added to electric vehicles in order to improve pedestrian safety. In the United States, these regulations are embodied in a National Highway Transportation Safety Administration document, FMVSS-141. This document provides guidance on the 1/3 octave-band frequency content, overall SPL, and measurement procedures that must be followed for a vehicle to be certified. This talk will present the results of a listener test with 16 participants who pressed a button upon detection of an approaching vehicle equipped with a FMVSS-141 compliant additive sound. Results are presented at probability of detection versus distance. This provides a unique view of the effectiveness of these sounds and additional aspects of this problem such as additive sound contribution to noise pollution and listener false alarm rates. Lastly, the talk will cover difficulties with this type of outdoor testing and recommendations for conducting them in a virtual environment.

Experimental and numerical investigation on sound absorption characteristics of 3D printed coupled-cavity integrated passive element systems

In aerospace applications, most of the components are made of composite materials due to the high strength-to-weight ratio. However, those composite structures are poor in sound absorption; for instance, payload fairing used in the launch vehicle system experiences broadband noise. Tuned Helmholtz resonator (HR) is being used to control few dominant low frequencies, and other frequency is left untreated. In this study, the acoustic mode of the rectangular cavity has been suppressed by a novel design of integrated passive elements (IPEs), which comprises a Helmholtz resonator, micro-perforated panel, and polyurethane foam. The proposed design reduces the noise level in Low-Mid-High frequencies, which is more efficient than passive elements used to control a single target frequency. The integrated passive components fabricated using the 3D printing technique are tested experimentally in an impedance tube to quantify the sound absorption coefficient, and the results are compared with the theoretical result. Further, the study presents a simplified approach for numerical simulation of fabricated samples coupled to a rectangular cavity system, which is validated experimentally. The overall sound pressure level (OSPL) results of the proposed design achieve 4–6 dB noise level reduction in [Formula: see text] octave frequency band.

Using noise control principles when evaluating the acoustic impacts of face coverings during the coronavirus pandemic

Several different combinations of face masks and shields are evaluated for their acoustic performance using a head and torso simulator (HATS). The HATS is used as a controlled and repeatable artificial sound source using white noise in a classroom environment. Sound pressure levels at octave band frequencies due to the face coverings are evaluated at a location of 2.0 meters from the HATS which is within the direct field to reduce the room acoustical effects. The problem is modeled as a barrier separating a source and receiver using fundamental noise control principles. Fabric material properties are used such as thickness, density, stiffness, and damping. The results are compared with experimental tests. The face shield with clear plastic barrier produces a resonance in the 1000 Hz octave band. Analytical models of cavity resonances, standing wave resonances, or plate resonances are calculated and compared with the experimental resonance. The speech interference level is used to determine the frequency content that is most likely to cause hearing difficulties and compared with A-weighted differences between the unmasked condition and masked.

Changes in Underwater Noise and Vessel Traffic in the Approaches to Halifax Harbor, Nova Scotia, Canada

Over the past two years, researchers at Fisheries and Oceans Canada have been running an acoustic monitoring project at multiple study sites throughout Nova Scotia, Canada to investigate baleen whale presence and levels of underwater noise. At the onset of the COVID-19 pandemic, a passive acoustic monitor (PAM) was in place in the study site located in the approaches to Halifax Harbor, a major Canadian port. This provided a unique opportunity to determine if changes in vessel noise levels occurred after pandemic restrictions were put in place. To investigate this, we analyzed and compared acoustic data collected from March 28 to April 28 and August 6 to October 22 in both 2019 and 2020. We also investigated possible changes in vessel traffic from February 1 through April 28 and July 1 through July 28 in 2019 and 2020 using terrestrial-based automatic identification system (AIS) data provided by the Canadian Coast Guard and cargo information provided by the Port of Halifax. The acoustic data were analyzed in 1/3 octave frequency bands. For the 89.1–112 Hz frequency band, we found an 8.4 dB increase in the daily minimum sound pressure level (SPL) in April 2020 compared to April 2019 due the presence of a large crane vessel stationed near the mooring site. For the period of August to October, we found an approximately 1.7 dB reduction in the same metric from 2019 to 2020. The most noticeable change in vessel composition was the dramatic decrease in the number and occurrence of pleasure craft in July 2020 compared to the same period in 2019. While this analysis looked at only a single PAM and a limited amount of data, we observed changes in sound levels in the frequency band known to be associated with shipping as well as changes in vessel traffic; we conclude that these observed changes may be related to pandemic restrictions.

Spiral sound-diffusing metasurfaces based on holographic vortices

In this work, we show that scattered acoustic vortices generated by metasurfaces with chiral symmetry present broadband unusual properties in the far-field. These metasurfaces are designed to encode the holographic field of an acoustical vortex, resulting in structures with spiral geometry. In the near field, phase dislocations with tuned topological charge emerge when the scattered waves interference destructively along the axis of the spiral metasurface. In the far field, metasurfaces based on holographic vortices inhibit specular reflections because all scattered waves also interfere destructively in the normal direction. In addition, the scattering function in the far field is unusually uniform because the reflected waves diverge spherically from the holographic focal point. In this way, by triggering vorticity, energy can be evenly reflected in all directions except to the normal. As a consequence, the designed metasurface presents a mean correlation-scattering coefficient of 0.99 (0.98 in experiments) and a mean normalized diffusion coefficient of 0.73 (0.76 in experiments) over a 4 octave frequency band. The singular features of the resulting metasurfaces with chiral geometry allow the simultaneous generation of broadband, diffuse and non-specular scattering. These three exceptional features make spiral metasurfaces extraordinary candidates for controlling acoustic scattering and generating diffuse sound reflections in several applications and branches of wave physics as underwater acoustics, biomedical ultrasound, particle manipulation devices or room acoustics.

Effect of noise and ototoxicants on developing standard threshold shifts at a U.S. Air Force depot level maintenance facility

Noise exposure has traditionally been considered the primary risk factor for hearing loss. However, ototoxicants commonly found in occupational settings could affect hearing loss independently, additively, or synergistically when combined with noise exposures. The purpose of this investigation was to determine the combined effect of metal and solvent ototoxicants, continuous noise, and impulse noise on hearing loss. Noise and ototoxicant exposure and pure-tone audiometry results were analyzed for U.S. Air Force personnel (n = 2,372) at a depot-level aircraft maintenance activity at Tinker Air Force Base, Oklahoma. Eight similar exposure groups based on combinations of ototoxicant and noise exposure were created including: (1) Continuous noise (reference group); (2) Continuous noise + Impulse noise; (3) Metal exposures + Continuous noise; (4) Metal exposures + Continuous noise + Impulse noise; (5) Solvent exposure + Continuous noise; (6) Solvent exposures + Continuous noise + Impulse noise; (7) Metal exposure + Solvent exposures + Continuous noise; and (8) Metal exposure + Solvent exposures + Continuous noise + Impulse noise. Hearing loss was assessed at center octave band frequencies of 500–6,000 Hz and using National Institute for Occupational Safety and Health Standard Threshold Shift (STS) criteria. Hearing changes were significantly worse at 2,000 Hz in the Metal exposure + Solvent exposure + Continuous noise group compared to the Continuous noise only reference group (p = 0.023). The Metal exposure + Solvent exposure + Continuous noise group had a significantly greater relative risk (RR) of 2.44; 95% CI [1.24, 4.83] for developing an STS at 2,000 Hz. While not statistically significant, the Solvent exposure + Continuous noise group had a RR of 2.32; 95%CI [1.00, 5.34] for developing an STS at 1,000 Hz. These results indicate that noise exposure may dominate hearing loss at ≥3,000 Hz while combined effects of concomitant exposure to ototoxic substances and noise are only noticeable at ≤2,000 Hz. These results also suggest combined exposures to ototoxicants and noise presents a greater hearing loss risk than just noise.

Analysis of Noise Level and Sound Transmission Loss (STL) of Noise Barrier Material for the Construction Site

The construction activities are commonly known as the noisy and annoying work that affects a human’s routine. Those students and lecturers whose location are at the noise receptor locations might be suffering from the health impairment. The objective of this study is to assess and determine the noise level present throughout the daytime period (9AM - 12PM and 2PM - 5PM) at respective measurement points. The analysis of noise spectrum of the sound source from 125 Hz to 4 kHz is part of the scope of study as well. The analysis was carried out by comparing the recommended safe noise level with the equivalent continuous sound level (LAeq) and sound pressure level (Lp) gathered from this study. By setting up a barrier to shield or enclose the sound source is the common way to control the noise transmission. Therefore, selection of the best noise barrier materials is based on the sound transmission loss (STL) value. In this study, the experiment STL of four different types of noise barrier material (newspaper, aluminium foil, cotton and EPS foam) also was carried out in the small scale of reverberation chambers equipped with the LMS Test Lab and LMS SCADAS Mobile device. The 16 tested one-third octave frequency band ranging from 125 Hz to 4 kHz had been utilized in this study. The results revealed that the material of newspaper produced the STL ranging from 0 dB to 9.7 dB within the low frequency of 125 Hz to 800 Hz. Meanwhile, the aluminium foil, had the optimum performance with at least 5.4 dB and above for the STL value at higher frequency ranging from 1 kHz to 4 kHz. Generally, the newspaper is considered as the best noise barrier material as it able to reduce the noise level more throughout the selected frequency range in this study.

Optimizing well-depth sequences for Schroeder diffusers using machine learning

Around mid-1970, Schroeder introduced a mathematical theory to generate sequences, which can compute the “depth of the Schroeder diffuser”. A Schroeder diffuser is a design consisting of a number of wells of different “depths,” which propagates sound energy in different directions. The Schroeder diffuser provides the ability to create an optimal scattering of the same sound energy in different diffraction lobes. This paper aims to exploit this property and optimize well-depth sequences from Schroeder diffuser using machine learning techniques. With the advent of machine learning and parallel computing, the optimization of sequences and the iterative process to select the optimal pattern of sequence can be done more efficiently. Hence, the primary focus of this paper is to come up with a machine learning model that predicts the scattered reflections from a random well-depth sequence surface and evaluates the quality of the scattered reflections using a diffusion coefficient. The model tries to achieve optimum diffuser properties by adjusting the sequence. The boundary element method can be used for computing the diffusion coefficient. The diffusion coefficient parameter determines the quality of the diffuser and can be calculated at ⅓ Octave frequency bands.

Acoustical transmission of face coverings used to reduce coronavirus transmission in a classroom environment

The COVID-19 pandemic has caused many communities to require the wearing of face coverings, masks, and/or shields indoors to reduce the transmission rate of the virus, which includes educators and students in classroom settings. Several types of face coverings are studied, including standardized N95 and KN95, assorted cloth, and clear plastic face shields. They are evaluated on an acoustical head and torso simulator (HATS) setup in a classroom with two different locations for monitoring via a sound level meter. The HATS is used as a controlled and repeatable artificial voice or sound source, which creates white noise, artificial speech, and real speech signals. Sound levels throughout the classroom are measured to determine the direct field and reverberant field regions, and they are compared to a room acoustics model. Attenuation at octave band frequencies due to the face coverings are evaluated at a location of 2.0 m from the HATS, which is within the direct field to reduce the room acoustical effects, with evaluations repeated at a location near the back of the classroom (6.2 m) to include those room acoustical effects. The acoustic effects of the face coverings are compared to reported droplet transmission rates.

Louvred Noise Barrier for Traffic Noise Reduction

Environmental issues near roads become more and more important in our society daily life. One of the most critical environmental issues is traffic noise. The present paper study louvred noise barrier designed by authors. The louvred noise barrier provides sound attenuation while allowing airflow and sunlight through it. Since the airflow resistance of the barrier is low, it requires a shallow foundation compared to conventional noise barriers. The sound attenuation performance of the louvred noise barrier was tested experimentally in a sound transmission chamber. Airflow resistance simulated using a computational fluid dynamics model. The simulation and experimental study were done with different louvred noise barrier setup: change of louvre blade angle and sound-absorbing material thickness. The results showed potential for future development for the field testing. Sound attenuation was highest in 2500 Hz and 3150 Hz octave frequency bands. Depending on the louvred barrier setup, sound attenuation was up to 28 dB(A) in mentioned frequency bands. The equivalent sound pressure level reduced up to 17 dB(A). The results showed that an increase in the louvre blade angle increases sound attenuation and increases airflow resistance.

Potential effects of underwater noise from wind turbines on the marbled rockfish (Sebasticus marmoratus)

Environmental assessments of underwater noise on marine species must be based on species-specific hearing abilities. This study was to assess the potential impact of underwater noise from the East China Sea Bridge wind farm on the acoustic communication of the marbled rockfish. Here, the 1/3 octave frequency band of underwater noise was 125 Hz with the level range of 78–96 dB re 1 μPa, recorded at distances between 15-20m from the foundation at wind speed of 3–5 m/s. Auditory evoked potential (AEP) and passive acoustic techniques were used to determine the hearing abilities and sound production of the fish. The resultes showed the lowest auditory threshold of Sebastiscus marmoratus was 70 dB at 150 Hz matching the disturbance sound ranging 140–180 Hz, which indicating the acoustic communication used in this species. However, the frequency and level of turbine underwater noise overlapped the auditory sensitivity and vocalization of Sebastiscus marmoratus. The wind turbine noise could be detected by fish and may have a masking effect on their acoustic communication. This result can be applied for further to the assessent of fish species released into offshore wind farm marine ranch.

The Immediate and Long-Term Impact of Military Aircraft Noise on Hearing: A Cross-Sectional Comparison of Fighter Pilots and Ground Staff

We examined the immediate and long-term impacts of military aircraft noise exposure on noise-induced hearing loss (NIHL) in fighter pilots and ground staff. We recruited 40 pilots, 40 ground staff, and 136 age-matched controls; all participants underwent hearing tests, including conventional pure-tone audiometry (PTA) (0.25–8.0 kHz), extended high-frequency (EHF) audiometry (9.0–18.0 kHz), and distortion-product otoacoustic emission (DPOAE) as a recent reference. A subsequent hearing test immediately after flight-mission noise exposure was requested. The results revealed higher recent hearing thresholds in pilots and ground staff than in controls. Threshold shifts at many octave band frequencies were also significantly elevated in ground staff. The grouped frequency threshold was significantly elevated in the 4–8 kHz high-frequency range. After a single flight-mission noise exposure, both ground staff and pilots showed decreased signal-to-noise ratios for DPOAE (1–8 kHz), whereas only ground staff showed significantly elevated left-ear hearing thresholds at 3, 11.2, and 12.5 kHz by conventional and EHF PTA. Fighter pilots and ground staff serve in hazardous noise-exposed environments that cause hearing damage and subsequent NIHL, but ground staff may be more vulnerable. A comprehensive hearing conservation program should be implemented to protect high-risk service members, and especially ground staff, from high-intensity noise exposure.

DEVELOPMENT OF THE METHODOLOGY FOR MEASURING NOISE LEVELS IN THE UNDERGROUND ROLLING STOCK

This document specifies the methodology for measuring equivalent sound pressure levels in octave frequency bands (in dB rel. 20 μPa), equivalent and maximum A-corrected sound levels (in dB rel. to 20 μPa), generated in the rolling stock in the driver’s cabins and in the passenger rooms of the salons, using acoustic meters - multifunctional analyzers Ecophysics, noise and vibration meters, spectrum analyzers Ecophysics 110A, Oktava 110A Eco, Oktava 110A, Oktava 111, B&K 2250, 2250L, 2270, noise and vibration analyzers ASSISTANT, noise and vibration meters, digital spectrum analyzers Algorithm-05, SVAN979. This methodology is applicable for noise measurements in the driver’s cabins and in the passenger rooms of the rolling stock of both new and old models operated by the underground railway.

Comparative analysis of Russian and foreign regulatory requirements for vibration protection of a tractor operator

The paper discusses the main requirements of Russian and foreign regulatory documents on vibration protection of the operator's workplace of wheeled and tracked vehicles. Their comparative analysis was performed. The normalization of the parameters of general vibration at the workplaces of operators of tractors and self-propelled agricultural vehicles in our country occurs in accordance with the requirements of SN 2.2.4 / 2.1.8.566-96, GOST 12.1.012-2004 and GOST 12.2.019-2015. The root-mean-square values of vibration accelerations for a certain period of exposure in each octave (one-third octave) frequency band are allocated as the evaluation criteria. They are compared for compliance with the regulated values from a specific standard. At the international level, the object of compliance is the ISO 2631-1: 1997 standard, which establishes the requirements for vertical and horizontal vibration with a certain exposure time on a person from 1 minute to 24 hours in the frequency range from 1 to 80 Hz. The article shows that the most stringent requirements for the level of local vibration are established in the Russian Federation. They provide clear regulation of the type of work performed, duration, magnitude, direction of existing loads, etc. Relatively soft requirements are in most European countries, except Poland, where the MPL is regulated taking into account the age, gender and condition of a person. In addition, in the regulatory documents of most foreign countries there are two and sometimes three indicators: threshold (upper and lower) values and MPL. When the threshold is reached, primary measures are usually initiated to counter harmful factors.

Determination of corrective optimals for Chinese university learners of English

In the expectation of investigating the nature of corrective optimals of the sounds of English for Chinese EFL learners, a small selection of problematic English vowel sounds (i.e. /ɪ/, /i:/, /e/, /æ/, /ʊ/ and /u:/) was explored. The present study investigated the corrective optimals for these sounds. To this end, an experiment was conducted. Thirty-seven first-year non-English major university EFL learners participated. Each student went through two diagnostic steps. First, each student’s preferred center frequency (fcenter) was determined for a particular vowel sound, beginning with exposure to the fcenter of the traditional native-speaker optimal. Second, a combination of frequency bands that together form corrective optimals for each of the six vowels was determined for each individual student. Rather than consisting of single continuous 1-octave bands, corrective optimals for Chinese university EFL learners were found to be discontinuous multiple frequency bands that are both narrower and finer. The corrective optimals for Chinese university EFL learners were identified as discontinuous multiple band structures containing a bandpass filter narrower than one octave and, in addition, a significant low frequency component. In the light of this finding, it seems valuable to reorient the concept of corrective optimal away from a single octave frequency band and toward discontinuous multiband structures containing a significant low frequency component. Further research over a great number of vowels and consonants for various languages is desirable to confirm and extend this finding.

Assessment of Pediatric Middle Ear Effusions With Wideband Tympanometry.

To determine if wideband tympanometry (WBT) can differentiate types of middle ear effusion (MEE): serous, mucoid, and purulent. Prospective cohort study. Tertiary care children's hospital. Children who met American Academy of Otolaryngology-Head and Neck Surgery's guidelines for ventilation tube insertion had WBT after anesthesia induction but before tympanotomy. MEE was categorized into 1 of 4 comparison groups: serous effusion, mucoid effusion, purulent effusion, or no effusion. WBT measurements were averaged to 16 one-third octave frequency bands, and comparison of the absorbance patterns for each MEE type was performed through a linear mixed effects model. A total of 118 children (211 ears) were included: 47 females (39.8%) and 71 males (60.2%). The mean age was 2.73 years (95% CI, 2.25-3.22); mean weight, 14.35 kg (95% CI, 12.85-15.85); and mean Z score, 1.13 (95% CI, -0.64 to 2.33). Effusions included 61 mucoid (28.9%), 30 purulent (14.2%), and 14 serous (6.6%), with 106 (50.2%) having no effusion. No significant differences were found for sex, race, age, weight, or Z score among the 4 types of effusion (P < .05). WBT showed a significant difference in median absorption among the effusion groups (P < .001), with a medium effect size of 0.35. WBT has potential use to differentiate types of MEE and should be studied further as a tool for investigating how the natural history and management of serous and mucoid effusions may differ.

АКУСТИЧНА ПОМІТНІСТЬ БЕЗПІЛОТНИХ ЛІТАЛЬНИХ АПАРАТІВ З СИЛОВИМИ УСТАНОВКАМИ НА БАЗІ ПОРШНЕВИХ ДВИГУНІВ

The presence in operation of many prototypes of UAVs with propeller propellers, the use of such devices at relatively low altitudes and flight speeds makes the problem of noise reduction from UAVs urgent both from the point of view of acoustic imperceptibility and ecology.The aim of the work is to determine a set of methods that help to reduce the visibility of UAVs in the acoustic range. It is shown that the main source of noise from the UAV on the ground is the power plant, which includes the engine and the propeller. The parameters of the power plants influencing the processes that determine the acoustic signature of the UAV were investigated. A comprehensive analysis of the factors affecting visibility was carried out. The power plants include two-stroke and four-stroke engines, internal combustion and two-blade propellers. The use of silencers on the exhaust of the internal combustion engine was considered. The spectral characteristics of the acoustic fields of the propeller-driven power plants for the operating sample of the UAV "Eco" were obtained. The measurements were carried out in one-third octave and 1/48 octave frequency bands under static conditions. The venue is the KhAI airfield. Note that the propellers that were part of the power plants operated at Reynolds numbers (Re0,75&lt;2*105), which can significantly affect its aerodynamic and acoustic characteristics. It is shown that when choosing a UAV control system, one should take into account the fact that two-stroke piston engines are the dominant source in the noise of propeller-driven control systems in the absence of a hood and mufflers in the intake and exhaust tracts. The use of a four-stroke internal combustion engine significantly reduces the noise of the control system. In the general case, the position of the boundaries of the zone of acoustic visibility of a UAV at the location of the observer is determined by the ratio between the intensity of acoustic radiation perceived by the observer from the UAV and the intensity of sound corresponding to the natural acoustic background and depends on the degree of manifestation of acoustic effects accompanying the propagation of sound in a turbulent atmosphere - the refraction of sound waves. Absorption and dissipation of acoustic energy. The calculation and comparison of the UAV detection range was carried out taking into account the existing natural maskers.The results of experimental studies are presented that allow assessing the degree of acoustic signature of the UAV. A set of measures aimed at reducing the intensity of the acoustic signature of the UAV in various regions of the radiation spectrum has been determined.

Exposure to nocturnal road traffic noise associated with the prevalence of hyperglycemia in Taichung, Taiwan

Background: Many studies have investigated the association between diabetes and exposure to road traffic noise, but few studies investigated the association between noise exposure at nighttime and at different frequency components. Objectives: This cross-sectional study elucidated the association between the prevalent hyperglycemia and nocturnal road traffic noise, and determined the impact from different noise frequency spectrum. Methods: We recruited 888 residents living in Taichung as the study subjects to collect personal information from the questionnaire and health examination. Land-use regression models were established to predict individual levels of full-frequency and octave-band frequency noise at nighttime and fine particles (PM2.5). The multivariable logistic regressions were conducted to estimate the odds ratio (OR) of prevalent hyperglycemia (fasting glucose level ≥ 100 mg/dL) after controlling for PM2.5 and potential confounders. Results: Participants exposed to nocturnal noise levels ≥ 62 A-weighted decibels (dBA) had a significantly higher risk of hyperglycemia (Adjusted odds ratio [AOR]=1.51, 95% confidence interval [CI]: 1.10-2.06) compared with the low-exposure group. Per one-interquartile range (IQR: 2.7 dBA) increase in night-time noise was associated with the increased risk of hyperglycemia (AOR=1.19; 95% CI: 0.98-1.45; p=0.08). In addition, participants exposed to 1-IQR (3.2 dB, 2.9 dB, and 1.8 dB, respectively) nocturnal noise at frequencies of 1000 Hz, 2000 Hz, and 4000 Hz had a significantly higher risk of hyperglycemia (all p values &lt;0.05), and those exposed at 4000 Hz had the highest risk (AOR=1.30, 95% CI: 1.02-1.66). Conclusions: The present study showed that exposure to nocturnal road traffic noise was associated with the increased prevalence of hyperglycemia, and noise exposure at 4000 Hz had the highest risk.