A simple cellular phone adapter to listen to heart and breathing sounds.

Download a frequency analyzer for your phone. (I have no affiliations with the following: Apple Store: iStethoscope, on Android: frequency analyzer with waterfall plot)

Usage

The center of the adapter must be placed over the microphone port. The adapter is an analog amplifier, taking the displacement of the skin over the large aperture and concentrating the pressure wave into the small aperture.

Notes

The membrane on many stethoscopes serves as a mechanical frequency filter, rejecting higher frequencies from breathing and voices. Since digital filters are equally effective - they are omitted from this design.

I am looking for partners. There is a significantly improved V2 design and eventually this will be a customizer with various presets loaded.