Abstract: A stethoscope head having a first pair of acoustical passages in sound communication with a low frequency sound receiving bell and a second pair of acoustical passages in sound communication with a high frequency sound receiving diaphragm. A cylindrical valve plug having a third pair of acoustical passages is disposed within a cylindrical bore into which the first and second pairs of acoustical passages open. A pair of sound tubes are connected to the third acoustical passages within the cylindrical valve plug. The pair of sound tubes act as a lever to facilitate rotation of the cylindrical valve plug to acoustically connect the third acoustical passages with either the first or second pair of acoustical passages.

Abstract: A stethoscope including a stethoscope head, a pair of ear tips, and binaural tube means providing two individually separate air passages including a longer passage and a shorter passage extending between the stethoscope head and each ear tip. A substantially U-shaped binaural yoke includes channel members for receipt of the binaural tube members whereby the longer tube can be retained within the yoke without producing any sharp bends which would cause a loss of sound transmission. the stethoscope is designed to be made entirely of plastic materials.

Abstract: A self-sealing dual stethoscope head including a low frequency sound receiving bell, a high frequency sound receiving diaphragm, a selectively movable valve including a cylindrical valve seat having a first acoustical passage in sound communication with the bell and a second acoustical passage in sound communication with the diaphragm, and a cylindrical valve member having a radial opening for selective alignment and sound communication with the bell acoustical passage or the diaphragm acoustical passage upon rotation thereof, the cylindrical valve member being characterized by having at least a portion of an arcuate lengthwise segment of diminished radius as compared to the remaining lengthwise portion of the cylindrical valve member, means for urging the cylindrical valve member into sound sealing contact with the first or second acoustical passages within the valve seat and means for locking the cylindrical valve members into position during alignment with an acoustical passage.

Abstract: A stethoscope is provided which includes a stethoscope head and a pair of ear tips which are connected by tube means which provide individually separate air passages from the stethoscope head to the ear tips. The length of each of the air passages is selected such that the resonant peaks of sound transmitted from the stethoscope head to one ear lie in the resonant valleys of sound transmitted from the stethoscope head to the other ear. This is achieved by utilizing separate air passages which have a length ratio in the range of about 0.63 to about 0.73. The stethoscope is preferably utilized in conjunction with a dual stethoscope head having a bell receiver for transmitting low frequency sounds and a diaphragm receiver for transmitting high frequency sounds.

Abstract: A stethoscope head having a bell and a diaphragm. The bell is offset from the diaphragm axis. The bell axis intersects the diaphragm axis at an acute angle of not less than twenty degrees or more than seventy degrees, and preferably at thirty degrees. A selectively movable valve is provided to connect the bell and the diaphragm, individually, to an airway which may be connected to a sound tube leading to binaurals. The valve comprises a cylindrical spool seated and totally supported within a cylindrical bore in the head body.