Normal. The two major sounds heard in the normal heart sound like âlub dubâ. The â lubâ is the first heart sound, commonly termed S1, and is caused by turbulence caused by the closure of mitral and tricuspid valves at the start of systole. The second sound,â dubâ or S2, is caused by the closure of aortic and pulmonic valves, marking the end of systole.
A subscript or superscript is a character (number, letter or symbol) that is (respectively) set slightly below or above the normal line of type. It is usually smaller than the rest of the text. Subscripts appear at or below the baseline, while superscripts are above.
The subscript 2 denotes a binary number. Each digit in a binary number is called a bit. The number 1010110 is represented by 7 bits. Any number can be broken down this way, by finding all of the powers of 2 that add up to the number in question (in this case 2, 2, 2 and 2).