STETHOSCOPE ACOUSTICS .2. TRANSMISSION AND FILTRATION PATTERNS
STETHOSCOPE ACOUSTICS .2. TRANSMISSION AND FILTRATION PATTERNS
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DOI：
10.1161/01.cir.34.5.899
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发表时间：
1966-01-01
期刊：
影响因子：
37.8
通讯作者：
STERN, AM
中科院分区：
文献类型：
--
作者：
ERTEL, PY;LAWRENCE, M;STERN, AM
This paper describes a fully calibrated and standardized acoustical test method for evaluating the transmission patterns and the filtration patterns of intact stethoscopes. An essential component of the test system is the artificial ear which duplicates the acoustical contribution of the average human ear to the stethoscope''s acoustics. The transmission patterns of bell-type stethoscopes fall into 4 distinct groups which correspond to their basic design features. Shallow bells and single tubing design both result in attenuation at higher frequencies. A deep, trumpet-shaped bell with double tubing design may provide amplification at higher frequencies. Diaphragms attenuate the transmission acoustics of stethoscopes. When the low frequencies are selectively attenuated, high frequencies are heard more distinctly. Some disphragms were found to attenuate at all frequencies. The acoustical performance of any stethoscope is critical. Any attenuation of clinically significant sounds of low intensity may render them totally inaudible. The majority of stethoscopes tested (bell and diaphragm chestpieces) attenuate high frequency sounds.
