Lets say I have a 5 hour audio recording of a radio channel. I want to track and count the no: of times a specific advertisement was played during the 5 hours. Is there a software to do this, where I copy the frequency clip of the specific ad, and then search the audio recording for that matching frequency clip? Please help. I tried Audacity, but I couldn’t find anything. So please help 
I’m going with no. Audacity doesn’t have the smarts to “know” what words are. To Audacity, they’re all blue waves on a timeline — or numbers whizzing by. I know of no tools that can compare a spoken phrase to all speech in a performance. Even if you could smash something together from programming parts, any difference between two seemingly identical sound sequences will kill you, like radio noise, MP3 compression differences or streaming management.
Koz
“find similar pattern” concept is not impossible to execute as Google can do that with images , ( admittedly not 100% successfully ).
http://en.wikipedia.org/wiki/Reverse_image_search
But “find similar pattern” not currently possible with Audacity.
If you look at the entire show , i.e. “Fit Project” , in spectrogram mode, ( rather than the default waveform display ), you may be able to spot where the advert breaks are as they may appear different from the rest of the show.