vs Traditional Stethoscopes

Comparison to Littman and Other traditional Stethoscopes

3M(TM) Littmann(R) Electronic Stethoscope, Model 3200BK

Stethoscopes have been used for over 200 hundred years. A full history can be found here.  Most current stethoscopes are based on advances made by Dr David Littman in the early 1960’s.

3M purchased his company in 1967 and has been selling Littman stethoscopes ever since. Littman digital cardiology stethoscopes are the most commonly used high-end stethoscopes.

Steth IO not only offers sounds of better acoustic quality than the Littman stethoscope, but also offers many other features not found in the Littman stethoscope — such as smartphone integration, real-time visualization, and improved usability.

Unified with the Smartphone

Since Steth IO is offered as a case for your smartphone and it can become the single device that a physician needs to carry. You don’t need to charge your stethoscope and by simply starting the Steth IO app, you can start auscultating.

With one hand, you can auscultate the patient while visualizing their heart and lung sounds. You can also use the included Bluetooth headphone to listen to the sounds as well.

With the Littman stethoscope, there is no smartphone app allowing you to collect or record the sounds on your smartphone platform. The Bluetooth streaming function in Littman is not compatible with the Apple device.

Real-time Visualization

Steth IO allows real-time visualization of the heart and lung sounds while auscultation. This visualization has been shown to improve provider confidence in diagnosing abnormalities compared to audio auscultation only.
The Littman stethoscope does not offer real-time visualization. Heart or lung sounds can be recorded on a PC connected via Bluetooth to the stethoscope. These sounds can be visually played back at a later time.


Steth IO offers many usability functions to make physical exam experience better. By default, the heart and lung sounds collected with Steth IO are digitized and recorded. A user can choose to annotate and save them so they share these sounds with experts with one or two simple clicks.

With the Littman device, saving and sharing involves multiple steps from connecting the device to a PC, collecting the recording on a PC, saving the file on the PC, to emailing the files from the PC.

Acoustic Quality

Frequency spectra of heart sounds are concentrated below 400 Hz, although they may extend up to 800 Hz. Frequency spectra of lung sounds generally peak below 100 Hz, although may extend as high as 2000 Hz. The central tenet of stethoscope-design is to amplify these frequency ranges of interest while attenuating background noise. Further, the frequency response must be smooth across the spectrum to avoid undesirable audio artifacts. The frequency response of Littman 3200 compared to the Steth IO device is shown in the Figure below.

The Steth IO also has a smoother frequency response, notably between 140 and 800 Hz. Although the Steth IO is more sensitive to frequencies above 1000 Hz than the Littmann 3200, subsequent user-testing found no complaints of higher-frequency background noise. Compared to the Littmann 3200, users also reported that the Steth IO had a more “natural timbre” and had similar acoustic qualities to the traditional stethoscopes to which they are habituated.

Patient Engagement

Steth IO has been shown to increase patient engagement significantly. Heart and lung sounds can be played back to the patients and abnormalities can easily be pointed out. The Littman device looks like a regular stethoscope and does not result in any improved patient engagement during a physical exam.



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