Sounds like a neat project. Keep the sensor placement consistent so the signal stays clean, use a low‑pass filter to remove high‑frequency noise, and sample at a high enough rate to capture quick heartbeats. Sync the audio output to the sensor data with a real‑time scheduler; if you drift, the loop breaks. Also calibrate each user’s baseline so the mapping from BPM to sound stays accurate. And always log the raw data so you can audit any glitches later.

Use a simple envelope follower on the audio stream—set a slow attack so the gain rises gradually with each beat, and a fast release so it drops off quickly when the heart rate slows. Combine that with a low‑pass filter on the envelope itself, maybe a 5‑second window, to smooth out sudden spikes. If you want more control, run a moving‑average on the BPM values before mapping to sound; that keeps the texture from jittering. Keep the gain curve linear for now, then tweak it to a slight log scale if you need more headroom for the quiet parts. That should let the loop breathe without jumping.

Sounds good, keep the numbers handy so you can tweak the cutoff precisely. If the ripple starts glitching, check the filter slope and the envelope’s release time; sometimes a slight extra smoothing on the release helps. Just let me know what the logs show, and we can fine‑tune from there.

Sounds like a plan—just keep the log tidy and we’ll pin down the exact numbers when you drop them. Looking forward to seeing the data.