Influence of Flow and High Sound Level on the Attenuation in a Lined Duct

1971 ◽  
Vol 49 (5B) ◽  
pp. 1643-1654 ◽  
Author(s):  
Ulrich J. Kurze ◽  
Clayton H. Allen
Keyword(s):  
Sound Level ◽  
High Sound

Quantifying Vocal Power: Correlation of Whole-Body Anaerobic Power to Vocal Function Measures

2020 ◽  
Vol 63 (8) ◽  
pp. 2597-2608
Author(s):  
Emily N. Snell ◽  
Laura W. Plexico ◽  
Aurora J. Weaver ◽  
Mary J. Sandage
Keyword(s):  
Fundamental Frequency ◽  
Forced Vital Capacity ◽  
Vital Capacity ◽  
Anaerobic Power ◽  
Performance Outcomes ◽  
Sound Level ◽  
Whole Body ◽  
Vocal Function ◽  
Laryngeal Diadochokinesis ◽  
High Sound

Purpose The purpose of this preliminary study was to identify a vocal task that could be used as a clinical indicator of the vocal aptitude or vocal fitness required for vocally demanding occupations in a manner similar to that of the anaerobic power tests commonly used in exercise science. Performance outcomes for vocal tasks that require rapid acceleration and high force production may be useful as an indirect indicator of muscle fiber complement and bioenergetic fitness of the larynx, an organ that is difficult to study directly. Method Sixteen women (age range: 19–24 years, M age = 22 years) were consented for participation and completed the following performance measures: forced vital capacity, three adapted vocal function tasks, and the horizontal sprint test. Results Using a within-participant correlational analyses, results indicated a positive relationship between the rate of the last second of a laryngeal diadochokinesis task that was produced at a high fundamental frequency/high sound level and anaerobic power. Forced vital capacity was not correlated with any of the vocal function tasks. Conclusions These preliminary results indicate that aspects of the laryngeal diadochokinesis task produced at a high fundamental frequency and high sound level may be useful as an ecologically valid measure of vocal power ability. Quantification of vocal power ability may be useful as a vocal fitness assessment or as an outcome measure for voice rehabilitation and habilitation for patients with vocally demanding jobs.

Study of the Acoustic Oscillations by Flows Over Cavities: Part 1 — Internal Flows

2002 ◽  
Author(s):  
Xavier Amandole`se ◽  
Pascal He´mon ◽  
Clotilde Regardin
Keyword(s):  
Lattice Gas ◽  
Acoustic Mode ◽  
Sound Level ◽  
Acoustic Oscillations ◽  
Helmholtz Instability ◽  
Internal Flows ◽  
Duct Acoustics ◽  
Neck Thickness ◽  
High Sound ◽  
Very High

We present a study of acoustic oscillations induced by an internal airflow over a shallow and a deep cavity. The Kelvin-Helmholtz instability is interacting with an acoustic mode of the duct, leading to a resonance which produces a very high sound level. The influence of upstream boundary layer thickness and neck thickness is studied. Some results obtained by modifying the upstream lip shape, by crenel addition, are also given. It is also shown that the numerical simulations using a lattice-gas method give relatively good results by comparison with the experiments. Especially the resonance with the duct acoustics was qualitatively reproduced.

The Sound Environment of the Foetal Sheep

Behaviour ◽  
1982 ◽  
Vol 81 (2-4) ◽  
pp. 296-315 ◽  
Author(s):  
B.A. Baldwin ◽  
B.C.J. Moore ◽  
Sally E. Armitage ◽  
J. Toner ◽  
Margaret A. Vince
Keyword(s):  
Sound Pressure ◽  
Body Wall ◽  
Low Frequency ◽  
Sound Level ◽  
The Body ◽  
Human Foetus ◽  
Low Frequencies ◽  
Sound Environment ◽  
High Sound ◽  
Foetal Lamb

AbstractThe sound environment of the foetal lamb was recorded using a hydrophone implanted a few weeks before term in a small number of pregnant ewes. It was implanted inside the amniotic sac and sutured loosely to the foetal neck, to move with the foetus. Results differ from those reported earlier for the human foetus: sounds from the maternal cardiovascular system were picked up only rarely, at very low frequencies and at sound pressures around, or below, the human auditory threshold. Other sounds from within the mother occurred intermittently and rose to a high sound pressure only at frequencies above about 300 Hz. Sounds from outside the mother were picked up by the implanted hydrophone when the external sound level rose above 65-70 dB SPL, and the attenuation in sound pressure was rarely more than 30 dB and, especially at low frequencies, usually much less. However, attenuation due to the transmission of sound through the body wall and other tissues tended to change from time to time. It is concluded that the foetal lamb's sound environment consists of (1) intermittent low frequency sounds associated largely with the ewe's feeding and digestive processes and (2) sounds such as vocalisations from the flock, human voices and other sounds from outside the mother.

scholarly journals How Wildlife Respond to Natural Noise

2021 ◽  
Author(s):  
Dylan G.E. Gomes
Keyword(s):  
Sound Level ◽  
Anthropogenic Sources ◽  
Anthropogenic Noise ◽  
Frequency Noise ◽  
Spider Webs ◽  
Predator Prey ◽  
Sound Levels ◽  
Natural Noise ◽  
Acoustic Environments ◽  
High Sound

Animal sensory systems have evolved in a natural din of noise since the evolution of sensory organs. Anthropogenic noise is a recent addition to the environment, which has had demonstrable, largely negative, effects on wildlife. Yet, we know relatively little about how animals respond to natural sources of noise, which can differ substantially in acoustic characteristics from human-caused noise. Here we review the noise literature and suggest an evolutionary approach for framing the study of novel, anthropogenic sources of noise. We also push for a more quantitative approach to acoustic ecology research. To build a better foundation around the effects of natural noise on wildlife, we experimentally and continuously broadcast whitewater river noise across a landscape for three summers. Additionally, we use spectrally-altered river noise to explicitly test the effects of masking as a mechanism driving patterns. We then monitored bird, bat, and arthropod abundance and activity and assessed predator-prey relationships with bird and bat foraging assays and by counting prey in spider webs. Birds and bats largely avoided high sound levels in noisy environments. Bats also avoided acoustic environments dominated by high frequency noise while birds avoided noise that overlapped with their song, the latter trend suggesting that communication is impaired. Yet, when sound levels were high overlapping noise was not any more disruptive than non-overlapping noise, which suggests that intense noise interferes with more than communication. Avoidance of noise that overlapped in frequency with song was stronger for low-frequency singers. Bats that employ higher frequency echolocation were more likely to avoid high sound level noise; we explore potential explanations for this pattern. Most arthropod Orders responded to noise, yet the directions of effects were not consistent across taxa. Some arthropods increased in abundance in high sound level areas - perhaps in response to the absence of bird and bat predators. Reinforcing this possibility, visually foraging birds and passively listening bats decreased foraging effort beyond what was expected based on declines in abundance and activity. Orb-weaving spiders increased dramatically in high sound level areas, which could be due to a release from predation, an increase in prey capture, or direct attraction to high sound level river noise. Overall, we demonstrated significant changes to many vertebrate and invertebrate taxa during playback of whitewater river noise. We were able to parse out the effects of sound pressure level and background frequency on these individual taxa and predator-prey behaviors. Our results reveal that animals have likely long been affected by particular characteristics of noise, which may help explain contemporary responses to anthropogenic noise. As the spatial and temporal footprint of anthropogenic noise is orders of magnitude greater than intense natural acoustic environments, the insights provided by our data increase the importance of mitigating noise pollution impacts on animals and their habitats. It is clear that natural noise has the power to alter animal abundances and behavior in a way that likely reverberates through entire communities and food webs. Future work should focus on strengthening the relationships between these potential predators and prey and highlight how the structure of the system changes under such noise treatments.

scholarly journals University Marching Band Members Noise Dosages and Hearing Health-Related Knowledge

2021 ◽  
Vol 18 (21) ◽  
pp. 11497
Author(s):  
Nilesh J. Washnik ◽  
Jeffrey A. Russell ◽  
Ishan Bhatt ◽  
Rebecca Meier ◽  
Olivia Chuzie ◽  
...  
Keyword(s):  
Sound Level ◽  
Marching Band ◽  
Band Director ◽  
Sound Exposure ◽  
Band Students ◽  
Sound Levels ◽  
Dose Limits ◽  
Health Related ◽  
Hearing Health ◽  
High Sound

Objectives: (1) To measure sound exposures of marching band and non-marching band students during a football game, (2) to compare these to sound level dose limits set by NIOSH, and (3) to assess the perceptions of marching band students about their hearing health risk from loud sound exposure and their use of hearing protection devices (HPDs). Methods: Personal noise dosimetry was completed on six marching band members and the band director during rehearsals and performances. Dosimetry measurements for two audience members were collected during the performances. Noise dose values were calculated using NIOSH criteria. One hundred twenty-three marching band members responded to a questionnaire analyzing perceptions of loud music exposure, the associated hearing health risks, and preventive behavior. Results: Noise dose values exceeded the NIOSH recommended limits among all six marching band members during rehearsals and performances. Higher sound levels were recorded during performances compared to rehearsals. The audience members were not exposed to hazardous levels. Most marching band members reported low concern for health effects from high sound exposure and minimal use of HPDs. Conclusion: High sound exposure and low concern regarding hearing health among marching band members reflect the need for comprehensive hearing conservation programs for this population.

Music to Our Ears: Are Dancers at Risk for High Sound Level Exposure?

2020 ◽  
Vol 35 (4) ◽  
pp. 227-232
Author(s):  
Haley Busenbarrick ◽  
Kathleen L. Davenport
Keyword(s):  
Hearing Loss ◽  
Performing Arts ◽  
Sound Pressure ◽  
Sound Level ◽  
Sound Recording ◽  
Exposure Limits ◽  
Moderate Risk ◽  
Sound Exposure ◽  
Daily Dose ◽  
High Sound

Enduring exposure to high sound pressure levels (SPLs) can lead to noise-induced hearing loss (NIHL). In the performing arts population, NIHL has been studied primarily in the context of sound exposure experienced by musicians and less so by dancers. This research aimed to identify sound exposure that dancers may experience in some dance classes. Decibel levels were recorded in 12 dance classes (6 ballet, 4 modern, and 1 soft and 1 hard shoe Irish dance) at 8 different studios using the NIOSH SLM app on an iOS smartphone with external microphone. A minimum of five recordings of each class was measured, each collected on a different day, yielding a total of 114 measurements. Results showed that 20.2% of all recordings exceeded the recommended NIOSH sound exposure limits of both 100% projected daily dose and 85 LAeq. Analysis between styles of dance demonstrated significantly lower LAeq (p≤0.05) in soft shoe Irish dance compared to ballet (p=0.023), modern (p=0.035), and Irish hard shoe dance (p=0.009). Irish soft shoe dance demonstrated minimal to no risk of high sound exposure. Conversely, 53.25% of ballet, 90.9% of Irish hard shoe dance, and 68.24% of modern recordings exhibited minimal to moderate risk of high sound exposure. Furthermore, we found wide ranges of projected daily noise doses within classes taught by the same teacher. It is recommended that multiple recordings of dance environments be obtained, as a single sound recording may not accurately represent potential exposure. These findings indicate that dancers of Irish hard shoe, modern, and ballet may benefit from noise intervention such as audiometric testing, noise controls, and hearing protection.

An Experimental Study of the Acoustic Oscillations by Flows Over Cavities

2004 ◽  
Vol 126 (2) ◽  
pp. 190-195 ◽  
Author(s):  
Xavier Amandole`se ◽  
Pascal He´mon ◽  
Clotilde Regardin
Keyword(s):  
Experimental Study ◽  
Boundary Layer Thickness ◽  
Acoustic Mode ◽  
Sound Level ◽  
Acoustic Oscillations ◽  
Helmholtz Instability ◽  
Deep Cavity ◽  
Neck Thickness ◽  
High Sound ◽  
Very High

We present an experimental study of acoustic oscillations induced by an internal airflow over a shallow and a deep cavity. The Kelvin-Helmholtz instability is interacting with an acoustic mode of the cavity or of the duct, leading to a resonance which produces a very high sound level. The influence of upstream boundary layer thickness and neck thickness is studied. Some results obtained by modifying the upstream lip shape, by crenel addition, are also given.

Optimizing Alarm Location and Effects of Hearing Protection for Machining Industries

2005 ◽  
Vol 49 (17) ◽  
pp. 1610-1614
Author(s):  
Jun-Seok Lee ◽  
Dongjoon Kong
Keyword(s):  
Hearing Loss ◽  
Sound Level ◽  
Working Environment ◽  
Location Problems ◽  
Hearing Protection ◽  
Noisy Environment ◽  
Alarm Systems ◽  
Protection Devices ◽  
High Sound ◽  
Timely Warning

Emergency alarm systems are extremely important in our daily life since these can provide adequate and timely warning to people in event of threatened disaster. These systems cause a traumatic hearing loss due to their extremely high sound level. Hearing protection devices are the most popular and convenient solution for avoiding a traumatic hearing loss. However, the study of alarm location problems with hearing protection has not been much paid attention. The purposes of this study were; (1) to determine the number of alarm devices, their optimum locations and minimum sound power levels and; (2) to find the effectiveness of hearing protection devices. The selected working environment was a machining facility that usually generates extremely high noise level. An analytical model was provided and the effects of hearing protection devices were discussed with two examples. The results showed that hearing protection was highly required at or above 85dBA noisy environment.

scholarly journals The Relationship between Sound and Amenities of Transit-Oriented Developments

2019 ◽  
Vol 16 (13) ◽  
pp. 2413 ◽  
Author(s):  
Yalcin Yildirim ◽  
Diane Jones Allen ◽  
Amy Albright
Keyword(s):  
Built Environment ◽  
Environmental Planning ◽  
The United States ◽  
Sound Level ◽  
Light Rail ◽  
Transit Oriented Development ◽  
Sound Levels ◽  
Level Of Significance ◽  
High Sound

Experts in diverse fields have investigated sound in cities throughout the United States. This research aims to examine sound levels and determine its contributors at the transit-oriented development (TOD) station and neighborhood levels by studying selected Dallas Area Rapid Transit (DART) light rail stations. A multilevel analysis was performed to model the likelihood of TOD stations and neighborhoods affecting sound levels, controlling for station amenities, socio-demographics and built environment characteristics. Sound measurements were sampled in three time intervals with 15 min sampling over weekdays and weekends at TOD and non-TOD stations by a type II SPL meter that was mounted on a small camera tripod at a height of 1.5 m, at a distance of 1.5 m from rails and curbs. The research team found that amenities, built environmental characteristics, and neighborhood features have significant implications on sound levels at both the TOD station and the neighborhood level, which affects quality of life (QoL). TOD stations that include more amenities have a greater level of significance on sound levels. Additionally, neighborhoods with a pervasive street grid configuration, public facilities, and built environment densities are significantly associated with a likelihood of high sound levels. Conversely, higher population densities and intersection densities decrease the likelihood of a high sound level environment. These patterns provide an arena for transportation, urban, and environmental planning and policymaking to generate transformative solutions and policies.

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