audio recognition with usb output

We will send you 5 audio files. Either using your own coding or downloading free software, recognise these sounds and create a "flag". For example, if we send you a sound of a dog barking, when the software is running, the next time the sound is heard, a pop-up will appear saying "dog barking". (fuzzy logic may be required as the sound may not be 100% the same each time... we can discuss this) We want this to be simple... very simple. If this can be done/proven, more is to follow. The code is to work on Windows XP. Enabling us to plug a device into the USB port to "read" the flag will be the next step. Please send us references/knowledge on this and we will decide if we are to go ahead and a more detailed brief will be sent. Thank you for reading my post.