A speech recognition system or method can include a speech input device and a processor coupled to the speech input device. The processor can be programmed to identify a plurality of words that are members of confusable pairs of words where each pair includes a target word and a substituted word. The processor can degrade a pronunciation of the substituted word to provide a worse pronunciation of the substituted word. The processor can further compare the pronunciation of the target word with the worse pronunciation to the substituted word. The processor can be further programmed to reduce confusion between the substituted word and other words in a recognition grammar of the speech recognition engine and can also narrow the scope within which the substituted word is recognized.