UNILEVER

When using a stethoscope with a tunable diaphragm, the healthcare professional does not have to remove the chestpiece from the patient in order to change from the bell to diaphragm mode. Also, single-sided chestpieces are shaped to provide a more comfortable grip for better feel and control. When listening to low frequency sounds with a tunable diaphragm there will be an increase in amplitude, or loudness. This is because the sound is coming through a diaphragm with a larger surface area. The sound pressure level increases with an increase in contact area on the patient.

Some Littman tubing is single lumen, or only having one opening and the high-end models are double lumen. The reason for double lumen design is the advantage in the sound quality when two separate tubes are used for listening to body sounds. An additional advantage to the Littmann stethoscope two-tubes-in-one design is that noise artifact created by separate tubes rubbing together is eliminated. The tubing in Littmann stethoscopes have never contained natural rubber latex or dry natural rubber as components, with the exception of an extension used on the Anesthescope and the Ploss monitor.

The correct way to use a Littman stethoscope is to use light pressure when auscultating with the bell, to hear low-frequency sounds. In order to hear high-frequency sound, the diaphragm should be used, applying firm pressure. As with a traditional bell, when using a stethoscope equipped with a tunable diaphragm, one should use light pressure to hear low-frequency sounds. Increasing the pressure on the chestpiece will cause the suspended diaphragm to move inward, resting on the internal ring of the chestpiece. When this happens, the low-frequency sound waves are attenuated, or reduced, allowing only the high-frequency sounds to be heard.