Speech recognition library for detecting phrase in file

I want to find all occurrences of a specific phrase in a set of audio files (it's a catch-phrase in a TV show). The phrase is pronounced by different people with different speed etc. What is the best approach to this problem?

Additional details: It's a one time thing. The end result should be a program that takes 30 hours of audio and produces timestamps of a particular short phrase. Obviously the training will be required. Problem is that while I'm a seasoned programmer I have pretty much no experience with speech recognition. I know that phoneme recognition engines exist will they get the job done? For now I need some pointers in the right direction.

• It's quite hard to answer your question because it is very general and you don't give much information. In principle you would need a fully-fledged speech recognizer that has been trained appropriately. Check out Sphinx, I think it's open source. – Matt L. Jun 7 '13 at 10:05
• @MattL. I've added some details. – synapse Jun 7 '13 at 20:05
• Has anything simple turned up since June ? – denis Oct 30 '13 at 16:47

The detection of a particular phrase in records sounded by different people may necessitate a complex speech recognition operation. Even if you train a good acoustic model, there is no guarantee that you will obtain a good recognition performance because you would also need some textual content which will constitute the language model.