Sound Disturbance Research Articles

エンジン音の影響を抑制するタイヤ音パワースペクトルの車上計測

エンジン音の影響を抑制するタイヤ音パワースペクトルの車上計測

Effects of motorboat noise on foraging behaviour in Eurasian perch and roach: a field experiment

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 564:115-125 (2017) - DOI: https://doi.org/10.3354/meps11997 Effects of motorboat noise on foraging behaviour in Eurasian perch and roach: a field experiment Carin Magnhagen1,*, Kajsa Johansson1, Peter Sigray2 1Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences, 901 83 Umeå, Sweden 2Department of Underwater Research, Swedish Defence Research Institute, 164 90 Stockholm, Sweden *Corresponding author: carin.magnhagen@slu.se ABSTRACT: The negative impact of anthropogenic noise on marine animals is receiving increasing attention. In order to study the effect of motorboat noise on foraging behaviour in fish, we chose 2 species with different hearing abilities. The roach Rutilus rutilus has a better developed sense of hearing than the Eurasian perch Perca fluviatilis. The study took place in an inlet of the Bothnian Sea where boat traffic is almost absent. Groups of 6 fish were placed in field enclosures containing either one of the species or equal numbers of perch and roach. Half of each enclosure was covered with artificial vegetation. The fish were fed with pieces of saithe twice a day, both with and without the disturbance of an outboard motor. Sound pressure level and particle acceleration were measured for the motor, which was run at 2000 rpm. The trials were repeated for 5 d. Perch made fewer feeding attempts during noise exposure compared to controls in the single-species enclosures. As the experiment progressed, they gradually increased feeding and time spent in the open area, both with and without noise, indicating habituation. Habitat utilization was affected by the interaction of noise exposure and day. Roach responded to noise exposure with fewer feeding attempts, higher latency to enter the open area, and longer time spent in the vegetation compared to the controls without noise. Roach behaviour changed with time only when housed together with perch. This study, using authentic sound in a natural habitat, shows that noise exposure may affect the feeding behaviour of fish, that the response is species-specific, and that habituation and the presence of other species may modify the effects. KEY WORDS: Anthropogenic noise · Feeding activity · Field enclosures · Perca fluviatilis · Rutilus rutilus · Sound disturbance Full text in pdf format Supplementary material PreviousNextCite this article as: Magnhagen C, Johansson K, Sigray P (2017) Effects of motorboat noise on foraging behaviour in Eurasian perch and roach: a field experiment. Mar Ecol Prog Ser 564:115-125. https://doi.org/10.3354/meps11997 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 564. Online publication date: February 03, 2017 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2017 Inter-Research.

Wildlife monitoring with unmanned aerial vehicles: Quantifying distance to auditory detection

ABSTRACTThere is growing application of small unmanned aerial vehicles (UAVs) for detecting, enumerating, and monitoring wildlife. However, little is known about how the sound from UAVs may be affecting wildlife being studied. We quantified sound levels of 2 UAVs to determine minimum altitudes they can fly before being aurally detected by wildlife. We tested a small quadcopter (SkyRanger; Aeryon Labs, Inc., Waterloo, ON, Canada) and a fixed‐wing platform (eBee; Sensefly Ltd., Cheseaux‐sur‐Lausanne, Vaud, Switzerland) at the University of Calgary in Calgary, Alberta, Canada, between 1000 and 1200 hours on 27 September 2014. We modeled sound propagation and attenuation in relation to the lower hearing thresholds for 3 game species and 2 species of predators. Results indicate that the UAV sound levels differed in the lower frequency ranges, but were otherwise similar above 1.25 kHz. The domestic cat (Felis silvestris catus) has the lowest hearing threshold, with the capacity to hear both UAVs from the furthest distance; whereas, the mallard (Anas platyrhynchos) has the greatest hearing threshold, which means UAVs can be closer before being aurally detected. Because flying height is related to image resolution, our results indicate that the ability to detect some wildlife species may be affected by the need to fly higher to minimize sound disturbance, potentially requiring higher resolution cameras than those currently used. Also, additional flight permitting may be required if modeling indicates a UAV must fly at a greater height to avoid a behavioral response by the target species. © 2016 The Wildlife Society.

Response of tropical avifauna to visitor recreational disturbances: a case study from the Sinharaja World Heritage Forest, Sri Lanka

We investigated the impact of human recreational disturbances on the distribution of birds along a popular nature trail in Sinhararja World Heritage Forest, Sri Lanka. It was hypothesized that visual and noise stimuli caused by the presence of humans affect the distribution of avifauna associated with this nature trail. Nine circular plots of 25 m fixed-radius laid along the trail (0 m), and 18 plots laid perpendicular to the trail at 75 and 150 m intervals, were studied from March 2013 to January 2014. The degree of human recreational disturbances was assessed in terms of visitor group size (visual disturbance) and their noise level (sound disturbance). These disturbances were categorized along a four-point scale (no human disturbance, low, medium and high disturbance). The relationship between disturbance levels and the abundance of birds was statistically tested. ANOVA results revealed that the abundance of birds differed significantly under various intensities of recreational disturbances at each distance level. A significant negative correlation between abundance of birds and intensity of disturbance at 0 m distance suggests an avoidance of edge habitats by birds in the presence of humans. Abundance of birds increased at the 75 and 150 m distance levels with increasing disturbances occurring at the trail. Significant negative correlations were further observed between disturbance level and the abundance of birds in ground/understory and sub-canopy vertical strata of the forest at 0 m distance. Under high levels of recreational disturbance occurring at this trail, the abundance of birds near the trail declined significantly, while bird abundance in the interior of the forest increased. The sensitivity of individual bird species to visitor disturbances varied with the vertical stratum of the forest they usually occupy. Birds occupying the ground, understory and sub-canopy are particularly sensitive to recreational disturbances while bird species occupying the canopy and above are less vulnerable to recreational disturbances.

The effects of cochlear implantation in Japanese single-sided deafness patients: five case reports

Conclusion Cochlear implantation (CI) for Japanese single-sided deafness patients resulted in improved speech perception, increased sound localization accuracy, and reduced tinnitus handicap. Objectives This study reports results for five adult SSD cases with CI, focusing on the benefits they obtained in terms of speech recognition, sound localization, and tinnitus handicap. Methods Five Japanese patients meeting the eligibility criteria were included in this study. All patients were implanted with a fully inserted MED-EL Concerto FLEX28® implant (MED-EL, Innsbruck, Austria). Speech perception outcomes in noise, as well as sound localization and tinnitus disturbance, were assessed pre-surgically and at 1, 3, 6, and 12 months after CI activation. Results The Japanese monosyllable test score in noise improved gradually after implantation. In some cases, speech perception ability appeared unstable, particularly in the first 1–6 months after implantation. The sound localization ability showed marked improvement in all cases, with the disturbance to daily life caused by tinnitus also decreasing in all cases from the early post-operative period.

Knowledge, attitudes, behaviors, and noise exposure of baristas

Objective: To examine the daily noise exposure of baristas working in cafés, and to measure their knowledge, attitudes, and behaviors regarding hearing conservation and perceptions of noise in their work environment. Design: Fifteen baristas from six cafés in Portland completed the Knowledge, Attitudes and Behaviors questionnaire, a sound disturbance survey, and a structured interview to document perceptions of noise in the work environment. To measure daily noise exposure, a subset of eight participants wore a personal dosimeter for three different work shifts. Study sample: A total of 11 females and four males, aged between 19 and 36 years old (mean: 26.3, SD: 4.6) recruited from independently owned cafés in the Portland metro area. Results: Dosimetry measurements revealed Leq measurements between 71 and 83 dBA, with noise doses ranging from 4% to 74%, indicating that baristas are not exposed to sound levels above the regulatory criterion. Questionnaire results indicated that baristas have low awareness about the hazards of noise, are not opposed to hearing conservation, and rarely use hearing protection when engaged in noisy activities. Conclusions: Baristas here lacked the pertinent education and motivation to commit to invaluable hearing conservation practices.

Numerical study of leading-edge receptivity on the infinite-thin flat-plat boundary layer

The laminar-turbulent transition has always been one of the most concerned and significant research topics. Receptivity is the first stage of the laminar-turbulent transition process in the boundary layer, and also plays a key role in the laminar-turbulent transition. However, previous studies for leading-edge receptivity mostly focused on the external sound disturbances, while it is seldom to see the relevant research on the leading-edge receptivity to free-stream turbulence in the boundary layer which is universal in the free stream. In view of this, direct numerical simulation is utilized in this paper to study the leading-edge receptivity to free-stream turbulence exciting the Tollmien-Schlichting (T-S) wave in the boundary layer. The high-order high-resolution compact finite difference schemes based on non-uniform meshes and fast Fourier transform are used in spatial discretization, and the fourth order modified Runge-Kutta scheme is used in temporal discretization to solve Navier-Stokes equations for direct numerical simulation. Perturbation waves with short wavelengths, whose wavelengths are approximately one-third of the disturbance wavelengths of free-stream turbulence, are excited in the boundary layer under the free-stream turbulence; and our numerical results show that the dispersion relations, growth rates and neutral stability curve of the group of the excited perturbation waves with different frequencies are in line with the solutions obtained from the linear stability theory. These obtained numerical results confirm that the group of the excited perturbation waves with different frequencies are a group of T-S waves with different frequencies and the interaction between leading-edge of flat plate and free-stream turbulence to excite unstable waves in the boundary layer is one of the receptivity mechanisms. Furthermore, it is found that the amplitudes of the excited T-S waves in the boundary layer increase linearly with increasing the amplitude of the free-stream turbulence; while the normal wave number and incident angle of free-stream turbulence are approximately 60 and 20, the leading-edge receptivity coefficient KI reaches a maximum; and the values of leading-edge receptivity coefficient KI

How do we know when patients sleep properly or why they do not?

The importance of adequate sleep for good health and immune system function is well documented as is reduced sleep quality experienced by ICU patients. In the previous issue of Critical Care, Elliot and co-workers present a well done, largest of its kind, single-center study on sleep patterns in critically ill patients. They base their study on the 'gold standard', the polysomnography technique, which is resource demanding to perform and often difficult to evaluate. The results are especially interesting as the authors not only used polysomnography in a large sample but also, in contrast to others, excluded patients with prior sleep problems. They also recorded patients' subjective sleep experiences in the ICU and thereafter in the ward (validated questionnaires) with simultaneous data collection of factors known to affect sleep in the ICU (mainly treatment interventions, light and sound disturbances). Interestingly, but not surprisingly, sleep was both quantitatively and qualitatively poor. Furthermore, there seemed to be little or no improvement over time when compared to earlier studies. This study stresses the magnitude of the sleep problem despite interventions such as earplugs and/or eyeshades. Sound disturbance was found to be the most significant but improvable factor. The study highlights the challenge and the importance of evaluating sleep in the critical care setting and the present need for alternative methods to measure it. All that in conjunction can be used to solve an important problem for this patient group.

OVERVIEW OF NOISE POLLUTION IN THE METROPOLITAN REGION OF BELÉM-PARÁ IN 2006

Sound disturbance has been growing up for the last decades, mainly in the major urban agglomerations. In 2004, Belem was pointed out in an IBGE research as the noisiest capital of Brazil. Thus, with the aim of verifying the panorama of sound pollution on the Belém-Pará metropolitan region on the year 2006, research was done on the archives of the Gerência de Perícias Tecnológicas , from the Centro de Perícias Científicas “Renato Chaves ”, where the solicitations for sound pollution investigation were selected among all investigation solicited to the Núcleo de Crimes Ambientais , for the period of January 01 to December 31, 2006 concerning the Metropolitan Area of Belém, State of Pará-Brazil (RMB). It was collected 80 reports for the studied period, that sources of sound pollution comprised in the category entertainment were the most frequent in investigation reports solicitations, and along with category factory, held the first place, both with 22% of report solicitations made during the studied period.

Well-balanced schemes using elementary solutions for linear models of the Boltzmann equation in one space dimension

In the kinetic theory of gases, a class of one-dimensional problems can be distinguished for which transverse momentum and heat transfer effects decouple. This feature is revealed by projecting the linearized Boltzmann model onto properly chosen directions (which were originally discovered by Cercignani in the sixties) in a Hilbert space. The shear flow effects follow a scalar integro-differential equation whereas the heat transfer is described by a $2 \times 2$ coupled system. This simplification allows to set up the well-balanced method, involving non-conservative products regularized by of the stationary equations, in order to produce numerical schemes which do stabilize in large times and deliver accurate approximations at numerical steady-state. Boundary-value problems for the stationary equations are solved by the technique of elementary solutions at the continuous level and by means of the analytical discrete ordinates method at the numerical one. Practically, a comparison with a standard time-splitting method is displayed for a Couette flow by inspecting the shear stress which must be a constant at steady-state. Other test-cases are treated, like heat transfer between two unequally heated walls and also the propagation of a sound disturbance in a gas at rest. Other numerical experiments deal with the behavior of these kinetic models when the Knudsen number becomes small. In particular, a test-case involving a computational domain containing both rarefied and fluid regions characterized by mean free paths of different magnitudes is presented: stabilization onto a physically correct steady-state free from spurious oscillations is observed.

Research on Active Noise Control in Power Transformer

The problem of noise in power transformer was pay attention to by this paper. The paper presents the design methodology for the active noise control (ANC) of sound disturbances in power transformer. The active noise attenuation algorithm uses the framework of output-error based optimization of a linearly parameterized filter for feedforward sound compensation to select optimal location of sensor and demonstrate the effectiveness of active noise attention in a large power transformer. The ANC controller can automatically measure the sound disturbances and select the compensate parameters to realize the noise cancellation. With 220kV power transformer noise cancellation, for example, the simulating results prove that the ANC technology to cancel the noise in power transformer is an effective way.

Active noise control in a forced-air cooling system

This paper discusses the design methodology for the active noise control of sound disturbances in a forced-air cooling system. The active sound cancellation algorithm uses the framework of output-error based optimization of a linearly parametrized filter for feedforward sound compensation to select microphone location and demonstrate the effectiveness of active noise cancellation in a small portable data projector. Successful implementation of the feedforward based active noise controller on a NEC LT170 data projector shows a 20–40 dB reduction per frequency point in the spectrum of external noise of the forced-air cooling system can be obtained over a broad frequency range from 1 to 5 kHz. A total noise reduction (unweighted) of 9.3 dB is achieved.

Effect of a Noise Reduction Program on a Medical— Surgical Unit

This quasi-experimental study tested an intervention to reduce sound levels in an acute care hospital. A parallel pre- and posttest design with control group was used; patients and employees completed the Topf Adapted Sound Disturbance Scales, and environmental sound levels were recorded on a Quest 2900 Sound Level Meter. Treatment interventions included an educational PowerPoint presentation for employees, minor environmental acoustical alterations, and the use of a Quest 261 Sound Detector/Controller for behavioral modification. None of these interventions produced statistically significant changes in sound levels. Patients and employees reported slightly less disturbance due to noise postintervention on the treatment unit. The findings of this study support Philbin and Gray's suggestion that the use of sound-absorbing materials in the hospital's physical structure may be the most effective measure to reduce sound levels in the hospital setting.

Identification of aerodynamic sound sources: the key problem in noise control

Despite the recent advances in the noise control technology, the key mechanisms of aerodynamic sound emission remained poorly studied. The "well-recognized" methods of TCAA did not lead to any breakthrough in this topical problem, and what seems most disappointing, the family of "acoustic analogies" is still used by many for definition of aerodynamic noise sources, though the sufficient set of mathematical proofs has been given by the author that this model is wrong. Experimental approaches aimed at localization of aerodynamic noise sources, including the method of acoustic imaging via using a microphone array, are considered, and their inherent limitations are pointed out. Unfortunately, no current experimental technique enables one to measure instantly all sound sources and sound disturbances inside the zone of generation, and so the latter is often regarded as a kind of "black box". The two-medium nonlinear theory of aerodynamic sound, based on the original decomposition of each flow variable into two components, for unsteady background flow and for acoustic field, has been created, that promotes better comprehension of the noise generation phenomena and opens new ways in flow/noise control. The main properties of this theory are now indicated in comparison with the most detrimental delusions originated from "acoustic analogies".

A survey assessment of the incidence of fur-chewing in commercial chinchilla(Chinchilla lanigera)farms

AbstractChinchilla lanigeraintensive breeding programmes are affected by an abnormal repetitive behaviour called ‘fur-chewing’, yet the aetiology is still unknown and little scientific work has been published on this condition. Recent studies have supported the idea that fur-chewing is a stress-related behaviour. In the present study, we used a questionnaire survey in order to: 1) describe general aspects on the epidemiology of fur-chewing in Argentinian farms, and 2) identify which management and/or environmental factors within the breeding facilities may be influencing the occurrence of fur-chewing. The survey consisted of 28 questions focused on farm characteristics, environmental variables and husbandry routines, and was distributed to Argentinian chinchilla farmers. All quantitative variables were tested in a multiple logistic regression model. The mean incidence of fur-chewing was 4.32 ± 0.37% (n = 107 farms). Variables negatively related to fur-chewing were the breeder experience in the activity, the total volume of the facility, and the number of wood shaving changes per week. Positive relationships were found for space index, number of rooms in the facility and presence of different rooms for fur production and reproduction. Other tendencies suggested that farms with the presence of external sound disturbance nearby had higher incidence levels. Also, we detected a tendency towards lower numbers of affected animals with an increment in the provision of dusting baths per week. Finally, results suggested a female prevalence in the development of the behaviour.

An integrated optical microphone test-bed for acoustic measurements

A diffraction-based optical detection method for microphone applications has been demonstrated previously [Hall et al., J. Acoust. Soc. Am. 118, 3000–3009 (2005)]. This method, coupled with proper integration techniques can produce precision measurement microphones with 24 dBA noise levels and suitable bandwidths. Thus far, these characterization studies have been performed using experimental setups, which would disturb the acoustic field due to size and non-symmetric features. In these regards, previous optical microphone test beds have been inadequate experimental platforms. This has motivated the development of a more robust integrated instrumentation microphone package for future testing and characterization. In order to meet the size restrictions for such an optical microphone platform, vertical cavity surface emitting lasers are used as light sources and small photodiode arrays are used to detect intensity variations in refracted orders of the optical detection method. The overall dimensions and shape of the package are comparable to commercially available half-inch calibration microphones and impose minimal sound field disturbance. The design is adapted to allow simple replacement and remounting for multiple microphone testing including biomimetic directional microphones [Miles et al., J. Acoust. Soc. Am. 98, 3059–3070 (1995)]. [Work partially supported by NIH Grant 5R01DC005762-03 and the Catalyst Foundation.]

Are solar activity and sperm whale Physeter macrocephalus strandings around the North Sea related?

In the final decades of the last century, an increasing number of strandings of male sperm whales ( Physeter macrocephalus) around the North Sea led to an increase in public interest. Anthropogenic influences (such as contaminants or intensive sound disturbances) are supposed to be the main causes, but natural environmental effects may also explain the disorientation of the animals. We compared the documented sperm whale strandings in the period from 1712 to 2003 with solar activity, especially with sun spot number periodicity and found that 90% of 97 sperm whale stranding events around the North Sea took place when the smoothed sun spot period length was below the mean value of 11 years, while only 10% happened during periods of longer sun spot cycles. The relation becomes even more pronounced (94% to 6%, n = 70) if a smaller time window from November to March is used (which seems to be the main southward migration period of male sperm whales). Adequate chi-square tests of the data give a significance of 1% error probability that sperm whale strandings can depend on solar activity. As an alternative explanation, we suggest that variations of the earth's magnetic field, due to variable energy fluxes from the sun to the earth, may cause a temporary disorientation of migrating animals.

Automated hearing threshold estimation in newborns using extrapolated DPOAE input/output functions

A new method for automatically assessing hearing loss by means of extrapolated DPOAE I/O-functions was applied for the first time in newborns. DPOAE I/O-functions were recorded in 118 ears of 93 newborns (mean age 3 days) at 12 frequencies between 1 and 8 kHz. L(2) was varied between 20 and 65 dB SPL with L(1)=0.4L(2)+39 and f(2)/f(1)=1.2. Auditory thresholds were constructed using the estimated DPOAE threshold level from extrapolated DPOAE I/O-functions. Follow-up measurements were conducted in 15 ears 4 weeks later. The first measurement revealed a high-frequency hearing loss. The second measurement showed normal hearing function. This fact and the decrease of DPOAE level in the frequency range of the hearing loss, while keeping the compressive shape of the DPOAE I/O-functions, indicate that transitory sound conduction disturbance may be due to amniotic fluid. The method fulfils the essential criteria for screening newborn hearing. It is fast and easy to handle, and measurement and data analysis are performed automatically. Preliminary results suggest that the new method is able to differentiate between transitory middle-ear dysfunction and persisting cochlear disorders. Due to its better diagnostic capabilities in comparison to TEOAE, DPOAE, and FAEP, this method may provide a new instrument with which to make a fast evaluation of hearing function in children.

An experimental and theoretical study of shock-wave propagation through reactive gases under conditions causing a transformation of the flow structure

Experimental observations of the transformation of the structure of shock waves entering the discharge gap of either a transverse or decaying glow discharge are presented. It is found that the total impulse of the shock wave pressure remains constant. A variation in the speed of sound, that is, the shock wave velocity, at which total dispersion of the wave occurs is found to be nonmonotonous across the discharge gap. The times over which the wave structure keeps changing after switching off the discharge have been more accurately determined. On the basis of the obtained experimental data and earlier results, a conclusion on the mechanism of this effect has been drawn. This mechanism is related to the dispersion of disturbances making up the wave structure in a relaxing medium (such as the glow discharge plasma). On the basis of a theory of this kind of dispersion, using the experimental data, and comparing energetic and temporal characteristics of the internal states of the plasma under study and the mode of sound disturbances (which according to the experiment, are responsible for the effect), we have succeeded in determining the O2(a1Δg) state whose relaxation brings about this effect.

The character and consequences of disturbing sound sensations in retraction type middle ear disease

Objective: Transient sound disturbances are common but neglected symptoms in retraction type middle ear disease (R-MED). The aim of this study was to explore and describe their character, their individual consequences, and their role in the development of tympanic membrane retractions. Methods: Fifty-three subjects with manifest retractions and experiences of disturbing sound and ear sensations were interviewed. A qualitative method was used for analysis of the transcribed interviews. Results: Two different patterns emerged from the interviews. 1. Too weak sound was the least common and most tolerable disturbance. It occurred in 45% and was eliminated by Valsalva’s inflation. 2. Sudden and transient sensations of too loud and piercing sound, and intermittent autophony frequently caused intense and intolerable discomfort, which might in turn cause loss of control of speech and conversation. These types occurred in 74% and 60%, respectively, and were eliminated by evacuating the middle ear, for example by sniffing. Subjects who described too loud sound or intermittent autophony commonly preferred a retracted tympanic membrane position. This may explain why pressure equalization by swallowing, and inflation by Valsalva’s manoeuvre often elicited discomfort. Conclusions: Transient experiences of too loud sound or intermittent autophony may indicate a shift of sound preference towards the sound experienced at negative middle ear pressure, and an unreliable tubal function in the sense that it fails to stay closed to protect the ear from sounds and pressure variations in the nasopharynx. Such experiences of altered sound may trigger evacuation of the middle ear, which eliminates the sound disturbance. It is crucial to identify, interpret, and explain the disturbances correctly in the therapy and prevention of retractions, since habitual evacuation exposes the tympanic membrane to strong negative pressure loads and a subsequent risk of developing retraction.