Toilet flush detection via sound recognition MCU

Hi,
I want to build a toilet flush detection system using sound recognition microcontroller.
Is that possible to build this??
I was goolging for hours..but only thing that i found is speech recognition libraries which I don't think its necessary.
Also, I was thinking..using MSP430 to convert toilet flusing sound digital value (12~16bits) than using comparator to compare the values (w/ previous saved value)
need some help here......

Why would you want to do this? Use a mechanical switch that's connected to the flushing mechanism. Using sound to detect the flushing is like a Rube Goldberg machine.

Yeh ur right but my instructor wont let me....

You might observe the FFT of a bunch of toilet flushes and see what the levels and frequency ranges are. Record that frequency range and amplitude and use that as a reference when running FFT on real toilet flushes. Not sure how accurate that would be though. Maybe time ranges too since some toilets start to sound different around the end of the flush.

Certainly beats simply triggering whenever there is a loud prolonged sound in the washroom since that coudl also be a blow dryer, or a shower.

If you're stuck with acoustic mapping, dkn's suggestion is the best.