def contrast(self, amount=<NUM_LIT>):
if not is_number(amount) or amount < <NUM_LIT:0> or amount > <NUM_LIT:100>:<EOL><INDENT>raise ValueError('<STR_LIT>')<EOL><DEDENT>effect_args = ['<STR_LIT>', '<STR_LIT>'.format(amount)]<EOL>self.effects.extend(effect_args)<EOL>self.effects_log.append('<STR_LIT>')<EOL>return self<EOL>
Comparable with compression, this effect modifies an audio signal to
        make it sound louder.

        Parameters
        ----------
        amount : float
            Amount of enhancement between 0 and 100.

        See Also
        --------
        compand, mcompand