Show HN: Live breath detection and biofeedback from a phone microphone (github.com)

67 points by felixzeller ↗ HN
Hi everyone, I am Felix, a famliy doctor from ZH, Switzerland. A couple of month ago I started this little project called shii • haa, a breathing app that uses the phone`s microphone for live biofeedback

My prior work in emergency medicine and intensive care was closesly linked to breathing, mostly in critical situations... and let me to reevaluate my own way of breathing. over time one question popped into my mind: can medical knowledge and biofeedback make an app actually promote self-awareness instead of attaching your goals to the award system of the app.

it combines signal processing, a breathing state machine and ML. The state machine follows inhale, exhale and transitions in the mic signal. A quality layer rejects noisy or ambiguous windows before signals are used for feedback. All processing is done on-device, no speech or raw audio is uploaded.

What I'm trying to avoid is turning breathing into another score or game. The app gives feedback on rhythm, depth and regularity, but the point is more "notice what you are doing" than "perform well".

I'd be interested in feedback, especially from people who have worked on signal processing, health UX, or Android/iOS audio issues.

18 comments

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(comment deleted)
Sounds interesting. Unfortunately not available in my country in the Android app store. I live in The Netherlands. If you're looking for feedback, you might want to double check this :)
OT did GitHub change their default fonts? This MD file shows up "differently" than I am used to, today.
Very interesting idea, I hope you can progress this into a well working, proven application.

I tried to do something very similar a year or 2 ago, more directed towards meditation. (Ie as a helper that uses breath to detect a wandering mind). A microphone in itself wasn't sufficient in my case, and detection was quite hard. I ended up using wired earbuds with microphones.

Nice focus as well, less scoring and more signal. All the best in your project!

Audio normalizing seems to be quite hard for this kind of use. I tried this 20 yrs ago with parts of a (mouse-)pointer device, a rigid nylon strap around the chest and 8 cm of flexible length in between. Mouse pointer wheel (one dimension only) was driven by change of length. For some hours of fiddling it was quite reliable.
What about in call centre situations to monitor employees or customers’ emotional states, or fingerprinting customers?
Sounds interesting. App not available in my region (iOS, Germany).
An update after the feedback here: I added ATMOS, a BIOS-style command layer for the browser version of shii•haa: https://shiihaa.app/atmos/ It explains how to open the interface: no login requirements, no availability issues. Thanks again to everyone. It helped shape the interface.