Decibel Levels Research Articles

Differences in early auditory exposure across neonatal environments

BackgroundTo date, no study has compared preterm and full term auditory environments. AimTo define differences in auditory exposure for preterm infants at term equivalent age in the neonatal intensive care unit (NICU) compared to auditory exposure in hospital rooms on a labor and delivery ward after full term birth. Study designNinety-eight infants (48 preterm infants born 28 weeks gestation in the NICU at term equivalent age and 50 full term infants in a hospital room on the labor and delivery ward within 4 days of birth) had auditory exposure measured over a single 16-hour period using the Language Environment Acquisition (LENA) device. ResultsMore language (p < 0.001) was observed on the labor and delivery ward than in the NICU, with an average of 3.3 h more language in a 16-hour period and an average of 14,110 more words spoken around infants in a 16-hour period on the labor and delivery ward (p < 0.001). More electronic sounds were observed in the NICU, with an average of 2.3 h more in the 16-hour period (p < 0.001). The average decibel level in the NICU was lower than in the hospital rooms on the labor and delivery ward (57.16 ± 2.30 dB, compared to 63.31 ± 2.22 dB; p < 0.001). ConclusionThe NICU auditory environment for preterm infants is different than the auditory environment for full term infants, with less language, more electronic sounds, and quieter stimuli. This understanding can aid in developing appropriate interventions that enhance positive forms of auditory exposures.

Auditory brainstem responses in weaning pigs and three ages of sows.

Piglet crushing is a devastating welfare concern on swine farms; however, some sows appear unresponsive to a piglet’s call. Sow hearing ability is rarely considered despite the extensive body of research performed on crushing. In this study, pigs of four age groups (weaning, n = 7; gilts, n = 5; 2nd and 3rd parity, n = 5; 5th parity and up, n = 5) were anesthetized and auditory brainstem responses (ABRs) were performed to measure if pig hearing diminishes with age in a mechanically ventilated barn. Before testing, pigs were placed in a sound dampening box. ABRs were performed on animals using 1,000 clicks at two decibel (dB) levels: 90 and 127 dB sound pressure level. Latencies and amplitudes of waves I–V were measured and interpeak latencies for waves I–III, III–V, and I–V were calculated. Five pigs (three 2nd and 3rd parity, and two 5th parity and above) had no detectable waves at either decibel. Sows in 2nd and 3rd parities had very few distinguishable waves, with only wave I and II present in two sows. Amplitudes of waves I and V increased with increased dB (P < 0.001). Increasing dB decreased the latency of each of the recorded waves (P < 0.01). The vast majority of commercial swine are raised in noisy barn environments; it is possible that these environments directly affect the ability for pigs to hear and normal hearing development in this population of animals. Hearing has a significant effect on swine welfare as hearing is integral to successful animal handing and during moments of animal-to-animal communication. Hearing is a considerable welfare issue on farms and ways to decrease pig hearing loss should be considered.

Incorporating acoustic objectives into Forest Management Planning when sensitive bird species are relevant.

BackgroundThe potentially negative effects of timber harvesting on biodiversity and habitat conservation leads to the consideration of a wide range of restrictions to forest logging in natural areas. In particular, high noise levels produced by forest machinery present a challenge to developing sustainable forest management plans. The Cinereous vulture (Aegypius monachus), the largest bird of prey whose nests are located in mature trees, is considered to be appropriate as an indicator species for environment-friendly forest planning. In this work, we evaluated spatially differences in sound propagation between stands. We hypothesized that differences due to the influence of orography in mountainous forests would allow the relaxation of spatial and temporary restrictions to timber logging, without causing any great disturbance at nesting sites of sensitive species.MethodsOur study was conducted in a Scots pine (Pinus sylvestris) forest of Spain, where an important colony of the Western European population of Cinereous vulture is located. We built 62 noise maps to characterize noise pollution due to tree logging at planning level. We modeled two different scenarios, in order to characterize; (i) the effect of a chainsaw operator during a complete cycle for felling a tree (Scenario 1), and (ii) the effect of the peak level produced by the breaking noise emitted by the trunk of the tree and its impact on the ground (Scenario 2). A strategy of three logical steps was designed; (i) landscape-scale analysis of noise propagation in stands, (ii) hierarchical cluster analysis of stands, (iii) assessment of the potentially significant influence of noise management in timber harvesting.ResultsThe minimum distance (DIST) from chainsaw operator sites to the 40 dB(A) contour lines was the only variable that had a significant influence on the clustering results. On the other hand, mean values of a newly proposed metric called average radius or radial distance (ARD) oscillated between 174 m in cluster #1 (Scenario 1) and 407 m in cluster #2 (Scenario 2).DiscussionOur results highlight the convenience of considering noise modeling tools at a forest planning level in order to address the compatibility of forest logging and the necessity of protecting nature. We found that spatial propagation of noise made by chainsaws at felling sites does not differ between stands even in a mountainous terrain, contrary to what we initially hypothesized. However, temporary logging restrictions could be excluded in about 36% of the current conditioned management areas according to ARD results in Scenario 2 (400 m). This proposal could be based on a sound pressure level (in decibels) criteria instead of conventional buffer protection distance criteria. In addition, it is suggested that the current size of restricted management areas could be generally extended from a 100 m radius to a 200 m one around the Cinereous vulture nest sites.

Quality Improvement Initiative to Reduce Nighttime Noise in a Transplantation and Cellular Therapy Unit.

Sleep is an essential biologic function vital for physiologic rest, healing, and emotional well-being. Sleep disruption is commonly seen in patients and caregivers with lengthy hospital stays such as patients undergoing hematopoietic stem cell transplantation and cellular therapy (TCT). Sleep disruption can lead to increased stress and fatigue, affecting caregivers' ability to support their loved one. The global aim of our quality improvement initiative was to improve sleep quality in TCT patients and caregivers. The smart aim of our project was to decrease nighttime hallway noise from 47 dB to 43 dB and decrease the number of overnight noise peaks greater than 60 dB from 865 to 432 in 6 months. Through a cross-sectional quantitative and qualitative evaluation of sleep we had previously identified poor sleep quality, and with a cross-sectional focus group analysis of patients, caregivers, and medical staff we identified the factors associated with poor sleep. Hallway noise was a major factor. A simplified failure mode analysis identified 4 main key drivers; unobtrusive nighttime cleaning process, nighttime awareness maintenance system, quiet nighttime nursing system, and reliable nighttime awareness system. Several plan-do-study-act interventions took place and were adopted. From January to June 2018 the overnight mean decibel level decreased from 47 dB to 44 dB (6% reduction). Overnight noise spikes above 60 dB decreased from a mean of 865 spikes to a mean of 463 spikes (46% reduction). With a quality improvement initiative, we identified the causes of hallway nighttime hospital unit noise that negatively impact sleep and through a team-based approach performed interventions that successfully mitigated these factors.

Supporting healthier urban environments with a sound and noise curriculum for students

ABSTRACT While urban environments do indeed have sounds that are exhilarating and exciting, people also comment that these environments are too often loud and uncomfortable. New York City excites people with the sounds accompanying the Macy’s Day parade and the celebration at Times Square on New Year’s Eve but its subway din, traffic roars, and sirens garner many complaints. With noise impacts increasingly being recognized as harmful to mental and physical health, urban centers have introduced measures to lessen the din of their cities. As an educator, I long recognized that one should enlist young people in our efforts to lower the decibel level. Thus, I was delighted to work with the New York City Department of Environmental Protection’s education arm on their curricula for school children, from the low grades through high school, that would teach them about the beauty of the good sounds and the dangers of loud sounds and noise. This article introduces readers to the Sound and Noise Module which can be accessed at the New York City’s Department of Environmental Protection site. The lesson plans on the Sound and Noise Module are a worthwhile read for all people interested in working towards a quieter and healthier society.

Festival “noise” and soundscape politics in Mumbai, India

ABSTRACT Issues of soundscape hold special significance in the daily lives of residents of Mumbai, India. “Noise pollution” has become an integral concept in how many Mumbaikars understand and frame auditory experiences of the city, and anxieties over sound figure prominently in public discourse, with local news media and Bombay High Court legal proceedings often fervently debating over the topic. Unlike other large cities with high ambient decibel levels, however, Mumbai’s noise pollution most visibly (and audibly) concerns sound from religious sources, most notably Hindu religious festivals taking place during a lengthy “festival season”. Close examination of this “festival noise” situation reveals a vastly intricate system involving political strategy, community imagination and labour politics.

Hazardous noise exposure from noisy toys may increase after purchase and removal from packaging: A call for advocacy

ObjectivePrevious studies identified hazardous noise levels from packaged toys. Sound levels may increase when packaging is removed and therefore, complicate the ability to accurately assess noise levels before purchase. The goal of this study was to evaluate how packaging affects the decibel (dB) level of toys by: 1) Assessing dB level of toys with and without packaging. 2) Evaluating the percentage of packaged and unpackaged toys that exceed a safety limit of 85 dB. MethodsThirty-five toys were selected from the 2009–2011 Sight and Hearing Association (SHA) based on availability for purchase. Toys’ speakers were categorized as Exposed, Partially Exposed, or Covered, based on its packaging. The dB level of each toy was tested at 0 cm and 25 cm from the speaker using a handheld digital sound meter in a standard audiometric booth. T tests and ANOVA were performed to assess mean change in sound level before and after packaging removal. ResultsSignificant dB increases were noted after packaging was removed (mean change 11.9 dB at 0 cm; and 2.5 dB at 25 cm, p < 0.001). Sixty-four percentage of Covered toys (n = 14) had dB greater than 85 dB when packaged and this increased to 100% when unpackaged. ConclusionMany manufactured toys have hazardous sound levels. Caregivers and healthcare providers should be aware that toys tested in the store may actually be louder when brought home and removed from their packaging. Limits on and disclosure of dB level of toys should be considered nationally.

Exposure to neighborhood green space and sleep: evidence from the Survey of the Health of Wisconsin

IntroductionAdequate sleep duration and quality are protective against many adverse health outcomes. Many individual-level predictors of poor sleep have been examined, but few studies have examined neighborhood-level influences. Despite known associations between neighborhood green space and sleep influencing factors (eg, physical activity, mental health), few studies have examined green space and sleep's relationship. Furthermore, little work has examined the relationship between the magnitude and type of neighborhood sounds and sleep. Study methodsWe analyzed data from the Survey of the Health of Wisconsin database (n = 2712) for 2008-2013, a representative sample of Wisconsin residents ages 21-74. Outcomes included weekday and weekend sleep duration and self-rated sleep quality. Primary predictors were the proportion tree canopy (National Land Cover Database) and mean decibel levels of outdoor sound (US National Park Service) at the census block group level. Survey regression analysis was used to examine statistical associations, controlling for individual and neighborhood-level covariates. ResultsModels suggest a significant relationship (P < .05) between weekday sleep duration and green space, and between weekend/day sleep duration and human-made and total neighborhood sound. Increased percent tree canopy in a census block group was associated with lower odds of short weekday sleep (<6 hours) (OR 0.76 [0.58-0.98]). Increased human-made and total mean decibel levels were associated with increased instances of short weekend and weekday sleep (OR 1.05 [1.01-1.08] and 1.03 [1.01-1.06] respectively). ConclusionsNeighborhood tree canopy and sound levels may influence sleep duration and are potential targets for neighborhood-level interventions to improve sleep.

Noise levels in veterinary operating rooms and factors that contribute to their variations.

To quantify noise levels in veterinary operating rooms (OR) and evaluate factors affecting them. Pilot study. Seventy-seven small-animal surgical procedures at the University of Florida College of Veterinary Medicine Small Animal Hospital. A decibel-measuring device was used to measure mean A-weighted, median, and maximum decibel readings within the OR. The number of people present in the OR, the number of people scrubbed in, the surgery service, and whether or not music was playing were recorded. The mean, median, and maximum decibel levels for all surgeries were 71.7 A-weighted decibels [dB(A)], 69.4 dB(A), and 90.3 dB(A), respectively. Neurologic surgeries were associated with higher noise levels. OR with music playing were louder than those without music (P < .001). None of the other factors evaluated were associated with noise levels. Neurological surgeries and playing music in the OR were associated with higher noise levels. The average noise levels in our veterinary OR were high and exceeded World Health Organization (WHO) recommendations. This is the first published study to quantify noise levels in a veterinary OR. Noise levels that exceed WHO recommended levels warrant additional investigation for potential side effects on surgical patients and OR staff.

Tone-Evoked Acoustic Change Complex (ACC) Recorded in a Sedated Animal Model.

The acoustic change complex (ACC) is a scalp-recorded cortical evoked potential complex generated in response to changes (e.g., frequency, amplitude) in an auditory stimulus. The ACC has been well studied in humans, but to our knowledge, no animal model has been evaluated. In particular, it was not known whether the ACC could be recorded under the conditions of sedation that likely would be necessary for recordings from animals. For that reason, we tested the feasibility of recording ACC from sedated cats in response to changes of frequency and amplitude of pure-tone stimuli. Cats were sedated with ketamine and acepromazine, and subdermal needle electrodes were used to record electroencephalographic (EEG) activity. Tones were presented from a small loudspeaker located near the right ear. Continuous tones alternated at 500-ms intervals between two frequencies or two levels. Neurometric functions were created by recording neural response amplitudes while systematically varying the magnitude of steps in frequency centered in octave frequency around 2, 4, 8, and 16kHz, all at 75dB SPL, or in decibel level around 75dB SPL tested at 4 and 8kHz. The ACC could be recorded readily under this ketamine/azepromazine sedation. In contrast, ACC could not be recorded reliably under any level of isoflurane anesthesia that was tested. The minimum frequency (expressed as Weber fractions (df/f)) or level steps (expressed indB) needed to elicit ACC fell in the range of previous thresholds reported in animal psychophysical tests of discrimination. The success in recording ACC in sedated animals suggests that the ACC will be a useful tool for evaluation of other aspects of auditory acuity in normal hearing and, presumably, in electrical cochlear stimulation, especially for novel stimulation modes that are not yet feasible in humans.

Acoustic comfort evaluation modeling and improvement test of a forklift based on rank score comparison and multiple linear regression

Aiming at the common problems of the engineering vehicles with high environment noise and poor acoustic comfort, this paper proposes an acoustic comfort subjective evaluation method based on rank score comparison (RSC) and develops a corresponding software system; it provides the solution method of evaluation modeling and improvement measure based on multiple linear regression (MLR). The actual application case of 50 noise samples from forklifts is presented to verify the feasibility and effectiveness of the RSC method. Through the subjective evaluation experiment, calculation of psychoacoustic parameters and data statistical tests, acoustic comfort evaluation model is established based on MLR. Consequently, the most significant parameter and improvement measure of acoustic comfort are obtained by means of sensitivity analysis and noise spectrum analysis. Finally, the improvement test of a target prototype is carried out and results indicate that the acoustic comfort has been improved obviously and the noise decibel level has met the industry standard requirement.

The Decibel Levels of TV and the Elusive Social Will

There is no dearth of media TV channels for the news of happenings around us. Through the din and noise of the TV commercials and the intermittent serials, we get news trickling down, often not any events or historic moments but the political cog mire of parliamentary or legislative arguments and the media interviews trying to brow beat any politician. Or the so called discussion in which the decibel levels of shouting matches take place! ; The media has a pet phrase ‘the public wants to know’, but often it may the least of interest for common people to know. The people at large would like to know if there is a fall in vegetable or grocery prices or improvement in industrial production or employment. But people often have to content with the Political or Advertisement Commercial noise! What people want to know is when this will stop and there will be realistic report of news. It is a nightmare experience for the TV and media viewers to contend with rising noise level often leading to switching off. Social will is absolutely necessary. This article is to find out if there is any solution for this problem!

Headphone Evaluation for App-Based Automated Mobile Hearing Screening.

Introduction With the need for hearing screenings increasing across multiple populations, a need for automated options has been identified. This research seeks to evaluate the hardware requirements for automated hearing screenings using a mobile application. Objective Evaluation of headphone hardware for use with an app-based mobile screening application. Methods For the purposes of this study, hEAR, a Bekesy-based mobile application designed by the research team, was compared with pure tone audiometric tests administered by an audiologist. Both hEAR and the audiologist's test used 7 frequencies (125 Hz, 250 Hz, 500 Hz, 1,000 Hz, 2000 Hz, 4,000 Hz and 8,000 Hz) adopting four different sets of commercially available headphones. The frequencies were regarded as the independent variable, whereas the sound pressure level (in decibels) was the dependent variable. Thirty participants from a university in Texas were recruited and randomly assigned to one of two groups, whose only difference was the order in which the tests were performed. Data were analyzed using a generalized estimating equation model at α = 0.05. Results Findings showed that, when used to collect data with the mobile app, both the Pioneer HDJ-2000 (Pioneer, Bunkyo, Tokyo, Japan) ( p > 0.05) and the Sennheiser HD280 Pro (Sennheiser, Wedemark, Hanover, Germany) ( p > 0.05) headphones presented results that were not statistically different from the audiologist's data across all test frequencies. Analyses indicated that both headphones had decreased detection probability at 4kHz and 8kHz, but the differences were not statistically significant. Conclusion Data indicate that a mobile application, when paired with appropriate headphones, is capable of reproducing audiologist-quality data.

How noisy are total knee and hip replacements?

Orthopaedic theatre can be noisy. Fifty percent of orthopaedic theatre staff have features of noise-induced hearing loss (NIHL). In this study, decibel (dB) levels were recorded in 17 total knee replacements (TKRs) and 11 total hip replacements (THRs). Noise levels reached 105.6dB(A) using a hammer and 97.9dB(A) with an oscillating saw. Exposure to levels above 90dB (which occurred in every case) even for short time periods is proven to cause irreversible loss of hearing. Tools used in orthopaedic theatre produce impulse noises that can cause NIHL. Further investigation is required.

An Efficient Workflow for Collecting, Entering, and Proofing Field Data: Harnessing Voice Recording and Dictation Software

An Efficient Workflow for Collecting, Entering, and Proofing Field Data: Harnessing Voice Recording and Dictation Software

Neuroanatomical Correlates of Hypophonia in Subcortical Vascular Cognitive Impairment

Background/Aims: Early detection and intervention may alter the disease course of subcortical vascular cognitive impairment (SVCI). Patients with SVCI have white matter ischemia that disrupts connections between the cortex and subcortical gray matter and therefore manifest various symptoms such as motor disturbances and behavioral/cognitive dysfunction. Reduced vocal loudness, or hypophonia, is one of the common motor symptoms of SVCI, but few studies have systematically investigated it in this patient population. The main purpose of this investigation was to identify neural pathways underlying hypophonia in patients with SVCI. Methods: Eighty-eight patients with SVCI and 21 normal controls performed phonation tasks. Diffusion tensor imaging data from 73 patients were utilized to measure white matter changes associated with hypophonia. Results: Correlational analyses between white matter fractional anisotropy values and the decibel level of the “sustained phonation” task identified the left midbrain cerebral peduncle (corticobulbar tract), external capsule, corona radiata/internal capsule, and bilateral frontal white matter as possible neural correlates for hypophonia. Conclusion: Our results support the notion that hypophonia in SVCI patients might be caused by the impairment of the pyramidal and extrapyramidal systems. This study provides a unique contribution towards understanding the neuropathology of hypophonic features in this population.

Clinician Perceptions of 4 Hearing Protection Devices.

Common equipment in the dental operatory generate cumulative noise at sufficient decibel levels that can damage hearing. Although noise exposure in the dental office is typically intermittent, dentists and other dental care providers have been shown to be at risk of hearing loss. This article provides dentist-generated insight to use when incorporating hearing protection devices during dental practice. Four hearing protection devices (HPDs) were provided to 15 dentists in randomized sequence for evaluation. Perceptions were gathered via questionnaires and analyzed to determine mean ratings and product preferences. Battery requirements of electronic HPDs were also examined. Qualitative assessments of the HPDs evaluated are presented, including dentist preferences and recommendations. There were statistically significant differences ( P ≤ 0.0031) among the HPDs in terms of ease of insertion, aesthetics, ability to hear while using a handpiece, and the openness of the ear. Battery life was not found to differ between the 2 electronic HPDs evaluated. Dentists most highly valued ease of hearing, ability to communicate, and comfort while wearing HPDs. The DI-15 High-Fidelity Electronic Earplugs HPD was ranked the highest, followed by Music PRO Electronic Earplugs. Battery longevity for these electronic HPDs was similar under all tested conditions studied. Knowledge Transfer Statement: Dentists should understand the potential ramifications of hearing loss and be aware that there are commercially available hearing protection products that preserve the ability to communicate with patients and coworkers.

Identifying Technical Condition of Vehicle Gearbox Using Acoustic Emission

The article examines the technical condition of rotating parts using acoustic diagnostics. The measured object was a mechanical transmission of a field vehicle. Recently this method has been developing very quickly and is expected to be used not only for the signal analysis itself, but also for the failure occurrence prediction which is our aim in the future. In our article we observe the technical condition of a four-speed transmission and analyse the acoustic signal expressed by the root mean square of a noise level in decibels.

Intergenerational preferences for radio loudness during automobile driving

IntroductionThe comparative contribution to human noise exposure from the vehicular radio is unknown, as are the radio volume preferences of different generations when driving an automobile. Materials and MethodsA single vehicle was used to measure radio listening level in decibels of three generations (age 16–17 years, age 32–50 years, and age 51–73 years) in various conditions, ranging from engine off with windows closed to 60 miles per hour (mph) with windows open. ResultsNo differences in radio loudness based on the sex of the driver were found. Statistically significant differences were identified in preferred signal to noise ratio among multiple vehicular paradigms, with the youngest generation preferring the largest signal to noise ratio in conditions with low background noise. ConclusionsThe youngest generation favored the largest signal to noise ratio (radio level above background noise), a preference which waned with increasing background noise.

Frequency tones and elevated decibel level of tones that are indicators of ill health or a state of health with associated pain

A correlation was confirmed in a study between noise sensitivity and ill-health. This study included clients that had hired an acoustic engineer to solve a noise problem, or patients who had a scheduled doctor’s appointment. Male and female patients in diverse outpatient specialty clinics including: Sports Medicine, Pain Medicine, Hematology &amp; Oncology and Breast Health were surveyed. The correlation shown of noise sensitivity to ill-health found was for a vast array of illnesses. A prior study was confirmed of a correlation of ill-health and noise sensitivity at lower frequencies that were typically only 1-2 dB(A) above ambient. Two additional findings were noted. First there was a heighted sensitivity to elevated noise levels of at least 15 dB(A) above ambient, such as construction noise, children screaming, sirens, etc. This noise sensitivity was found in people of various illnesses including but not limited to patients with cancer, atrial fibrillation, undescribed back pain, or untreated pain from a shoulder injury. The second finding was that some or all of the sensitivity dissipated upon treatment or remission of the illness or pain. This paper additionally discusses how to view this noise sensitivity as an indicator of ill-health, as well as influences on hospital design.