I see it as tetrary (4 components) short beep short silence (usually defined as the length of one short beep) long beep (usually defined as the length of 3 sho

I see it as tetrary (4 components) short beep short silence (usually defined as the length of one short beep) long beep (usually defined as the length of 3 short beeps) long silence (longer than two short silences)