Not sure if this happened to you, but for me, I always find myself composing a piece of music in my head and even humming it out while commuting or at somewhere inconvenient. This is something I made in Introduction to Physical Computing class called Music Composer Helper, which is a choker that can start recording automatically when it detects the user humming. It uses a piezo to detect the vibration on the neck of the user and uses a microphone to detect and record sound. It uses Kalman filter to reduce noise. The choker doesn’t begin recording until the sound volume and the level of vibration both reach the thresholds, and the audios will be saved to an SD card. This project was done in a very short period of time and was very simple, future work would be on more professional signal processing, safer physical design and easier usage. I also hope to develop a brain-computer interface application to export music directly from brain in the future.