Infrasonics

Stephens, R.W.B.

doi:10.1016/0041-624x(69)90525-3

Cited by 9 publications

(7 citation statements)

References 11 publications

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“…As discussed by Stephens (1969), high intensity infrasound can be produced by diesel engines or conventionally designed heating and ventilating systems in modern buildings. For example, many rooms within the author's university, particularly after ''retrofitting'' and ''renovations,'' produced infrasound pressure variations that exceeded 90 db during whole-building bulk air flow.…”

Section: Industrial and Cultural Sourcesmentioning

confidence: 99%

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Infrasound, human health, and adaptation: an integrative overview of recondite hazards in a complex environment

Persinger

2013

Nat Hazards

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Infrasound displays a special capacity to affect human health and adaptation because its frequencies and amplitudes converge with those generated by the human body. Muscle sounds and whole-body vibrations are predominately within the 5-to 40-Hz range. The typical amplitudes of the oscillations are within 1-50 lm, which is equivalent to the pressures of about 1 Pa and energies in the order of 10 -11 W m -2 . Infrasound sources from the natural environment originate from winds, microbaroms, geomagnetic activity, and microseisms and can propagate for millions of meters. Cultural sources originate from air moving through duct systems within buildings, large machinery, and more recently, wind turbines. There are also unknown sources of infrasound. It is important to differentiate the effects of infrasound from the awareness or experience of its presence. Moderate strength correlations occur between the incidences of infrasound and reports of nausea, malaise, fatigue, aversion to the area, non-specific pain, and sleep disturbances when pressure levels exceed about 50 db for protracted periods. Experimental studies have verified these effects. Their validity is supported by convergent quantitative biophysical solutions. Because cells interact through the exchange of minute quanta of energy that corresponds with remarkably low levels of sound pressure produced by natural phenomena and wind turbines upon the body and its cavities, traditional standards for safety and quality of living might not be optimal.

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Section: Industrial and Cultural Sourcesmentioning

confidence: 99%

“…Airborne sound of sufficient intensity enters the body by direct absorption and stimulates non-auditory tissue that produces physiological effects essentially similar to whole-body vibrations (Stephens 1969). The distinction between whole-body mechanical vibration and direct absorption from sound pressures becomes less important as the frequency is reduced.…”

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confidence: 99%

Infrasound, human health, and adaptation: an integrative overview of recondite hazards in a complex environment

Persinger

2013

Nat Hazards

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“…Ultrasonic radiation, unless it is extremely intense, does not appear to be a hazard to hearing. Infrasonic radiation, at a few hertz, can cause bodily effects similar to those discussed in the previous section (Stephens 1969).…”

Section: Interference Witti Bodiiy Jutictionsmentioning

confidence: 65%

Preparation of Low-Stress SiN_x Films by Catalytic Chemical Vapor Deposition at Low Temperatures

Takano

Niki

Heya

et al. 2005

Jpn. J. Appl. Phys.

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This article covers acoustic design from two main aspects: the design of acoustical devices such as microphones, loudspeakers, etc, and the principles for reduction of sound through partitions, in rooms, etc. These sections are preceded by a description of the behaviour of sound waves and vibrating bodies, and an outline of human response to sound. Finally, special problems in silencing and in the diagnostic use of sound are described. Acoustic design principlesVector velocity of element of source Absorption coefficient of a surface = p / p~, fraction of critical damping Angle of directivity of a dipole source Coefficient of resistive force in a vibrating system Value of p for critical damping of a vibrating system Frequencies of resonance in a rectangular room Density of air Phase lags in vibrating systems Angular frequency. 147 IntroductionThere are two main aspects to acoustical design. The first is concerned with the principles which can be applied to the practical realization of devices such as microphones, loudspeakers, etc, to enable them to work correctly: the second is concerned with the design of devices or structures to reduce noise. Since most problems of noise concern the human subject, the latter aspect of the work necessitates a knowledge of human reaction to noise.This paper deals only with acoustics in the audible region, approximately 20-20000 Hz. Ultrasonics is today virtually a technology on its own. both in communications and in 'sonics'-the term used for the application to engineering devices; while infrasonics (acoustical phenomena below the threshold of hearing) is beginning to develop.The first part of the paper deals with the behaviour of sound waves and the characteristics of random noise. Spectrum measurements and sound-level measurements are described, and human response to noise-ranging from annoyance, through speech interference, to damage to hearing-is outlined.The second part deals with the design of acoustical instruments such as microphones and loudspeakers; this is introduced by a section on the powerful technique of acoustical analogies.The third part deals with design from the point of view of the control of sound waves in auditoria and in transmission through partitions; anti-vibration methods are also described, and the section concludes with a brief review of special methods in silencing and in the diagnostic use of noise. Acoustic sources and fields 2.1. Magnitudes in acousticsOne of the problems in dealing with acoustics is that the physical quantities are so small. The often-quoted statement that the acoustical energy produced by the shouting of a Cup Final crowd would heat enough water to make a cup of tea is accurate enough; even the shouting voice produces an acoustic power of only milliwatts. Of course the aerodynamic energy-to say nothing of other forms of energy-in the process is vastly greater, but conversion efficiencies from aerodynamic to acoustical energy are in the region of 10-4 or 10-5 for many processes.It follows therefore that most acoustical measuremen...

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“…Although there are numerous sources that attend to this question in detail (Broner, 1978;Leventhall, 2007;Mühlhans, 2013;Stephens, 1969;Tempest, 1976), a brief overview shall be given in this review. Infrasound is the low end of the frequency spectrum.…”

Section: The Physics Behind (Infra-)sound -What Is Infrasound?mentioning

confidence: 99%

“…Depending on the field of research, the low frequency range is usually given from 0-1 to 100 Hz and infrasound in the frequency range below 16 or 20 Hz (Benade, 1976;Broner, 1978;Broner & Leventhall, 1982;Mohr, Cole, Guild, & von Gierke, 1965;Pimonov, 1974;Stephens, 1969;Tempest, 1976). A lower limit for infrasound is hardly ever given, but frequencies below 0.1 Hz are relevant for seismic or atmospheric monitoring rather than auditory or perception studies (Le Pichon, Blanc, & Hauchecorne, 2009).…”

Section: The Physics Behind (Infra-)sound -What Is Infrasound?mentioning

confidence: 99%

Low frequency and infrasound: A critical review of the myths, misbeliefs and their relevance to music perception research

Mühlhans

2017

Musicae Scientiae

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Over the last several decades low frequency and infrasound have become relevant to many fields of research-most recently psychology and musicology, among others. Interpretation of data from experimental research has raised concern that low frequency and infrasound could be potentially harmful to humans' well-being. While the physiological and psychological effects of infrasound are well documented, a variety of myths promulgated by pseudoscientific authors and newspapers still make it difficult to distinguish between fact and fiction, especially for people with little or no knowledge in acoustics. Myths are widespread today and result mainly from the one-dimensional view on sound, outof-context citations, and a number of "sensational" findings from biased studies. The aim of this review is to evaluate the relevance of data from a music-psychological and psychoacoustic point of view, to give a consistent overview of the history of research, to examine the transferability of findings, and to trace the origins of myths to debunk them. Additionally, general information about the characteristics of low frequency sound, its production, measurement, and difficulties in experimental research is given to avoid mistakes in future research.

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Infrasonics

Cited by 9 publications

References 11 publications

Infrasound, human health, and adaptation: an integrative overview of recondite hazards in a complex environment

Infrasound, human health, and adaptation: an integrative overview of recondite hazards in a complex environment

Preparation of Low-Stress SiN_x Films by Catalytic Chemical Vapor Deposition at Low Temperatures

Low frequency and infrasound: A critical review of the myths, misbeliefs and their relevance to music perception research

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Infrasonics

Cited by 9 publications

References 11 publications

Infrasound, human health, and adaptation: an integrative overview of recondite hazards in a complex environment

Infrasound, human health, and adaptation: an integrative overview of recondite hazards in a complex environment

Preparation of Low-Stress SiNx Films by Catalytic Chemical Vapor Deposition at Low Temperatures

Low frequency and infrasound: A critical review of the myths, misbeliefs and their relevance to music perception research

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Preparation of Low-Stress SiN_x Films by Catalytic Chemical Vapor Deposition at Low Temperatures