The bell is another circular end of the chestpiece. On two-sided chestpieces, the bell is the smaller end. Due to its smaller diameter, it has a more restricted range that focuses on lower frequency sounds than the diaphragm. Similar to the diaphragm, today’s bells now come with features that provide better comfort for patients as they’re being examined. The smaller size of the bell makes it ideal for pediatric patients and skinnier patients. It is also used when dealing with bandaged areas or the carotid area.
The stem is the part that connects the chestpiece to the stethoscope tubing. It is usually made of metal or steel. On stethoscopes with two-sided chestpieces, it is also the part that allows the user to choose between the diaphragm and the bell. This is done by simply rotating the chestpiece and then clicking it into place with a ball bearing. Rotating the chestpiece determines whether the diaphragm or bell directs sound to the eartubes.
The tubing is responsible for transferring and relaying the frequencies or sounds picked up by the chestpiece. It directs the sounds to the eartubes so that the user can hear them.
Stethoscopes often come with either a single tube or dual lumen tube design. With dual lumen tubing, the tubing is actually split in half on the inside, creating two sound channels inside one outer tube. This creates left and right paths so that the sounds can reach the user’s ears with the greatest accuracy. Stethoscope tubing these days is designed to withstand skin oils and alcohol, making them longer-lasting and able to endure constant use and cleaning.
Headset, Eartubes, And Eartips
The headset is that half of the stethoscope often seen hanging from a healthcare professional’s neck. The headset is composed of two eartubes, tension springs, and eartips.
The eartubes connect the stethoscope tubing to the eartips. They are made of metal or steel and are designed to be at the optimal angle for the best fit into the user’s ear canals. The eartubes isolate and direct the sounds into left and right paths to provide the user a clearer and more accurate listening experience. They have ribbed ends where the eartips are then placed.
The eartips are the parts that actually go into the ear. They are usually made of rubber or silicone and have a hole in the middle for letting out sound. Eartips are placed on the ends of the eartubes to provide an acoustic seal as well as to improve user safety. Eartips should provide a snug but comfortable fit for the user. They often come in different sizes to accommodate different ears.