What triggers a vibration from my wristband? How far away can sounds be and still trigger a vibration?

The sound's pitch, loudness, and the wristband's sensitivity level determine if the wristband will pick up a sound. You can change the wristband's sensitivity by using the PLUS and MINUS buttons. If you want to feel everything around you, increase the sensitivity to level 3 using the + button. If you want to feel fewer sounds, lower the sensitivity to level 1 using the - button.