Picking out the heartbeat *acoustically* will be extremely difficult. Since it sounds like direct contact is allowed, consider other technologies. My Polar heart monitor is low cost and transmits the heartbeat by radio to a compatible receiver. Old tech, very reliable.

ak

Hey, I legit created an account here to ask you this question (I saw you are still active on this forum).
I'm also trying to have my heartbeat play on a speaker in real time for a research project and I'm seeing my best option might be the Polar heart monitor. How does it transmit the heartbeat by radio to a compatible receiver / what would be a compatible receiver? Thank you!

Moderator edit: new thread created from here.

 

I fixed an electronic stethoscope project. I used an ordinary electret mic (not the unknown one from Amazon) and glued it to the lid from a peanut butter jar. The lid blocks background sounds.

 

I fixed an electronic stethoscope project. I used an ordinary electret mic (not the unknown one from Amazon) and glued it to the lid from a peanut butter jar. The lid blocks background sounds.

Hey, thanks for your answer. I know nothing about electrical circuits and believe I don't have the knowledge to build one. Contact mics didn't work, the heartbeat wasn't picked on. I'm considering buying a heart rate monitor like Polar H9 but am not sure if there are compatible apps so I can hear the heartbeat in real time, which is important because my idea is to accelerate and slow down my heartbeat with breath work (I'm a profesional dancer and starting an artistic residency with that intention). Any tip is welcome!