It’s not easy to find information online on how to record a heartbeat. I decided to run a little experiment just with the recording gear I already have at home and report my results.
The results were completely unexpected, at least for me.
The only method that worked for me was recording with my phone.
Now I don’t have tons of fancy recording gear, but I have done quite a bit of home recording and I expected the thousands of dollars I’ve spent on recording gear to actually come in handy for this task, but it turned out I just didn’t have what was needed.
And if my one successful recording isn’t enough for you, I found a couple other successful attempts from others. You can scroll to the end of the article to see them.
Attempt 1: My Phone with Voice Recorder App (Remember to Remove Your Phone Case)
I already had a recording app on my phone (I use it to record daily affirmations) so why not give it a try? It wasn’t going to cost me anything but a few minutes of my time.
I just booted up the app (I use the Android Voice Recorder app), stuck my phone’s recording microphone on my chest and started recording.
This attempt was a complete failure. I got some sound, but it I couldn’t tell if any of it was from my heartbeat or not. Some of the sound was definitely just the phone movement against my skin, but I there were some faint beats that may or may not have been my heart.
I tried several times and the result was the same every time.
But wait, I still had my phone case on!
The phone case put about 5mm of open space between the phone’s microphone and my body. That’s certainly enough to cause a problem. I removed my phone case and tried again. This time I was able to get an actual recording of my heart rate, yay! This is what I got:
So first of all, this is not the original recording. I had to convert the original M4A file to an MP3 file, so this file has gone through one conversion.
Second, there is a lot of static in this recording. It’s actually quite difficult to hear the heartbeat. I have to crank up my phone volume to really hear anything.
If you want to record your heartbeat to show the doctor or just hear it for yourself, this is probably satisfactory for you. But if you want to put your heartbeat in a recorded piece of music (like me) or something along those lines, you’re going to want a much cleaner recording.
Attempt 2: Make My Own Stethoscope (Failure)
After my last attempt it was clear to me that I needed some assistance to make the sound of my heart louder, so my next idea was to make a stethoscope. I watched this video and made something similar:
I had high hopes for this method, but in hindsight I shouldn’t have. I couldn’t hear anything in the stethoscope. There was just not enough sound gathered and too much sound lost in this homemade stethoscope design.
If you want to utilize a stethoscope, you would need to buy a medical one. The cheapest ones I could find were about $100. And even then I have a feeling you would need to buy a more specialized microphone to really get a good recording.
For me, it simply wasn’t worth $100 or more to record my heartbeat, so I decided to just move on and work with what I already owned.
Attempt 3 and 4: Mics I Already Had at Home (Both Failures)
I’ve done a decent amount of recording music I write and perform myself, so I have a few vocal mics at home. I also recently asked for an outdoor recording device and received a Tascam DR-05X as a gift, so I’ve been looking for reasons to try it out.
I wouldn’t say either of these mics are ideal for recording a heartbeat, but I still wanted to see if I could improve on the recording I got with my phone.
So what happened?
Vocal Mic
When I first set up the vocal mic, I was already skeptical that it would work. Why?
Well because the microphone has nearly a 360 degree sound field. What I really want is a microphone that can focus in one direction. Not to mention my microphone, while reasonably high quality, is made for live sound. So it’s made to really cut out a lot of extraneous noise, which is kind of what we’re trying to record.
Needless to say, the trials with the vocal microphone didn’t pick up anything.
I tried to amplify the signal any way I could and tried filtering out unwanted frequencies, but I just never managed to hear a heartbeat.
This is clearly not the way to record a heartbeat.
Outdoor Mic
You wouldn’t expect an outdoor mic to be able to pick up a heartbeat just based on the label, but I actually had some higher hopes for this mic. It does try to pick up sound from all around, but based on the shape of the mics alone I thought it might actually be a success.
See how the two microphones are flat? I hoped (wrongly) that being able to press the microphone flat on my chest would give the device a good chance of catching some of my heartbeat.
I was wrong.
This was another failed attempt. I tinkered with the recording settings several times, but I was never able to hear a heartbeat.
I guess the lesson here is that to record your heartbeat you need a recording instrument that can press directly against your skin and block out ambient noise.
Option Not Attempted: Recording Stethoscope
In my search for various ways to record a heartbeat I came across one product in particular that can record your heartbeat and sync with your phone. The product/brand was called Eko.
Basically, the product is made simply to record your heartbeat and then gather various medical information about it. It’s intended purpose is entirely medical. It’s supposed to monitor your heart rate and listen for any irregularities.
It’s not a product for a recording artist, but it might actually be one of the best options currently available for a recording artist. As far as I can tell the product is made like a medical stethoscope, but instead of sending the sound to an analog tube that gets passed to your ears, it simply converts the sound directly to a digital signal.
It’s hard to imagine a better process for getting a good heartbeat audio signal.
Successful Attempts From Others Online
I think the reason the phone microphone worked is because it is a one directional microphone that only has a small hole for recording. When I pressed the microphone on my chest it completely closed the hole off from the rest of the room.
With the failures of the home recording gear I have, I think I would go one of two routes to get a louder and cleaner heartbeat recording:
1. One directional mic put directly on your chest and clean up with recording software.
I did find a video from Amal Lad where he managed to get a recording of his heartbeat with only a microphone and some noise gates in his recording software.
I feel like this method should produce a better recording than the phone. Once you get a recording into your software you should be able to clean up the ambient noise and get a clean recording of your heartbeat. It’s probably worth saying that you should also be able to clean up the recording from your phone with your recording software as well.
2. Record heartbeat with a stethoscope
Anatoly Zolotkov creates a homemade DIY electronic stethoscope with parts from a stethoscope, a very small microphone and a Tascam recording device much like the one I have.
The results were quite incredible.
If you are serious about getting a high quality recording of your heartbeat this has to be the best way to go about it. There are quite a few parts necessary, but the final recording sounds great.
Conclusion
If you just want a low quality recording, you can record your heartbeat with only your cell phone and a recording app. You can also get a slightly higher quality recording with a directional recording microphone placed directly on your chest.
If you want a cleaner, higher quality recording you’ll need to get your hands on a stethoscope and a small directional microphone, or a product specifically designed for recording your heartbeat, like the Eko.
