I'm writing a speech recognition application and I give it possible words that the user could say. The problem is that it is too generous in allowing words through. If I tell the computer to listen for the word Koala, it will accept Kangaroo, Anaconda, and any other word that shares even a common syllable. I'm building a list of words so that when I tell it what word to listen for, I can also give it other words that are as far away from the correct word as possible to "distract" the computer away from giving me so many false positives. In short, is there an easy list of letter sounds that are as far away from one another as possible? As in, a list of "opposites" for letters? That way I can properly pull from my word list to give it good opposite words.
Any list, or any personal input would be greatly appreciated, as I'm no expert on the subject. I tend to stick with computers!