It is a digital comparator.That means it has two inputs, A and B. If voltage A is higher than B the the output is high, if voltage A is lower than B then the output is low.Sound is a constantly changing voltage so this chip by itself will not track any changes in amplitude.If you have a peak detectorhttp://www.allaboutcircuits.com/vol_3/chpt_3/5.html Then you could use this chip to trigger when th