Stethoscope

What is a stethoscope?

A stethoscope is a device healthcare providers use to listen to sounds inside your body. These sounds tell your provider a lot about many different aspects of your health — including how well your heart and lungs are working and whether blood is flowing normally through your arteries.

It’s likely a familiar scene — you’re at a medical appointment, and your provider reaches for their stethoscope. They press its small circle on different areas of your chest, back and belly. You breathe in slowly and then breathe out. Your provider may nod and then move on to the next part of the exam. Or they might show concern and want to investigate something further.

Providers — including primary care physicians (PCPs), nurses and paramedics — use stethoscopes every day. The stethoscope has become an enduring symbol of healthcare. But what exactly is your provider listening for, and why is this seemingly simple device so useful? Let’s take a closer look.

What is the stethoscope used for?

Healthcare providers use stethoscopes for auscultation. This is the medical term for the process of listening to internal body sounds. Specifically, providers use stethoscopes to listen to your:

• Heart
• Lungs
• Intestines
• Blood vessels

Your body is constantly producing sounds as part of its normal functioning — like the “lub-dub” of your heartbeat. But some sounds aren’t normal, and they could point to an issue that needs monitoring or treatment.

For example, a stethoscope allows your provider to hear abnormal:

• Heart sounds, like heart murmurs
• Lung sounds, like wheezing or stridor
• Intestinal noises, like grumbling or high-pitched sounds
• Blood flow through your arteries, like a carotid bruit

If your provider hears any of these sounds, they know something isn’t quite right. But they might not know the exact problem or how serious it is. So, they’ll run more tests to find out what’s happening and plan any needed treatments. This means the stethoscope is a valuable first step in diagnosis — but it’s typically not the only step. It provides clues that allow your provider to rule out concerns or investigate further.

What are the different types of stethoscopes?

There are several types of stethoscopes a provider might use.

Analogue stethoscope

Also called a traditional or classic stethoscope, this is the device most providers use. It’s the tried-and-true method for listening to internal body sounds.

There aren’t any electronic or digital components. Instead, sound travels directly from inside your body to your provider’s ears through flexible tubes. Your provider hears those sounds and decides what they mean.

There are variations on the classic stethoscope, like pediatric stethoscopes with smaller parts.

Electronic stethoscope

This is a more advanced stethoscope that amplifies internal body sounds so your provider can hear them more easily. It’s great for picking up subtle, softer sounds like certain types of heart murmurs.

This stethoscope also has built-in technology that reduces background noise that might interfere with the sounds your provider is trying to hear. It can record sounds for your provider to listen to later or share with other providers.

Digital stethoscope

This stethoscope has even more advanced technology to capture subtle sounds and tune out background noise. Like the electronic stethoscope, it can record sounds for later playback. But it can also convert sounds into visual data (like graphs) that help providers better understand what’s going on inside your body.

Plus, providers can download the data to computers or other devices. From there, they can use software to analyze the sounds and learn more. They can also share the data with your other providers to help coordinate your care.

In the future, more providers may use electronic and digital stethoscopes. For now, though, traditional stethoscopes are the mainstay in healthcare and provide plenty of valuable information to your providers.

How does a stethoscope work?

A stethoscope works by capturing sounds from inside your body and sending them through hollow tubing to your provider’s ears. The science of sound is complex, but in general, when something moves inside your body, it creates vibrations. These vibrations cause nearby molecules to bump into each other, creating sound waves. The stethoscope’s tubing is like a tunnel that transports the sound waves.

Your provider’s ears receive these sound waves and translate them into recognizable sounds — like the whoosh of a heart murmur or the high-pitched whistle of stridor.

The various parts of a stethoscope work together to make this all happen.

Stethoscope parts

The main parts of a traditional (analogue) stethoscope include:

Chest piece

This is the part that your provider gently places against your skin (commonly your chest but also your back, belly or neck). It’s made of metal and plastic. Like a coin, the chest piece typically has two sides: a diaphragm and a bell. Your provider can flip back and forth between them to hear different types of sounds.

The diaphragm is a flat circle, and the bell is a hollow cup. A short metal stem leads out of the chest piece and into the tubing.

Tubing

This is a hollow, flexible tube that carries sound out of the chest piece and toward your provider’s ears. There are some variations in design, but typically one tube leaves the chest piece and extends a bit before splitting into two separate tubes, forming a Y shape. These flexible tubes connect to the metal ear tubes.

Ear tubes

These directly carry sound into your provider’s ears. There are two metal tubes, one for each ear, with some tension between them. Your provider can squeeze the tubes toward each other or pull them farther apart to fit around their face. Each ear tube has a soft tip at the end (like earbuds you use when listening to music). These ear tips fit snugly into your provider’s ears.

Electronic and digital stethoscopes have these same basic parts, and you likely won’t notice a difference when your provider is using them on you. But these more advanced stethoscopes have other built-in technologies that do things like amplify sound or create recordings.

Who invented the stethoscope?

A French doctor named René Laennec invented the stethoscope in 1816. But his invention — a simple wooden tube — looks very different from the stethoscope your provider uses at your appointments. That’s because several other doctors improved upon the design over the years. In 1960, an American doctor named David Littmann developed the stethoscope design we use today.