Peak Signal Level

• The peak level of a signal $x$ is defined as:
  $$A_p \ensuremath{\stackrel{\Delta}{=}}\mbox{max}\{\vert x_n\vert\}_{n=0}^{N-1}$$

• This value is determined by finding the maximum of the absolute values of the signal over a time duration of $N$ samples. Peak levels can be positive or negative.