| Sound environment of the fetal sheep. | |
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MedLine Citation:
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PMID: 2301503 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The internal sound pressure levels within the intact amnion of pregnant ewes surgically implanted with a hydrophone was determined during conditions of quiet and during sound field exposures to broadband and octave-band noise. Measurements were made of sound pressures outside and inside the ewe, and sound attenuation through maternal tissues and fluids was calculated. Sound pressures generated by low frequencies (less than 0.25 kHz) were 2 to 5 dB greater inside than outside the ewe. Above 0.25 kHz, sound attenuation increased at a rate of 6 dB per octave. For 4.0 kHz, sound attenuation averaged 20 dB. The sound pressure recorded at different locations within the amnion with respect to the sound source varied by up to 6 dB. The internal noise floor in the absence of externally generated sounds was as low as 50 dB (spectrum level) above 0.2 kHz. Thus the fetus is developing in an environment that is rich with internal and external sounds. |
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Authors:
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K J Gerhardt; R M Abrams; C C Oliver |
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Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S. |
Journal Detail:
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Title: American journal of obstetrics and gynecology Volume: 162 ISSN: 0002-9378 ISO Abbreviation: Am. J. Obstet. Gynecol. Publication Date: 1990 Jan |
Date Detail:
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Created Date: 1990-03-13 Completed Date: 1990-03-13 Revised Date: 2007-11-14 |
Medline Journal Info:
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Nlm Unique ID: 0370476 Medline TA: Am J Obstet Gynecol Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: 282-7 Citation Subset: AIM; IM |
Affiliation:
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Department of Communication Processes and Disorders, University of Florida, Gainesville 32611. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Acoustic Stimulation Amniotic Fluid / physiology Animals Environment* Female Fetus / physiology* Noise Pregnancy Sheep / embryology Sound* Spectrum Analysis |
| Grant Support | |
ID/Acronym/Agency:
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20084//PHS HHS |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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