Each night is laid out like tracks in a music editor: one for sleep stages, one for heart rate and HRV, a few for the sensor events, and one for the noise events with the audio loaded in.

As an avid reader of aircraft accident reports (ok, more reader of blog posts and watcher of YouTube videos based on those reports - yeah, people have strange hobbies), it reminds me more of flight data recorder graphs - the first FDRs actually inscribed the graphs with needles on metal foil (https://aviation.stackexchange.com/questions/59289/was-the-f...), which is of course no longer the case, but the presentation has been kept.