Audio Comparison using Micorosft speech recognition engine

Audio Comparison using Micorosft speech recognition engine

I have an application in which user can speak and a word and he will be
given the percentage accuracy of the word he spoke. i.e how much clearly
the engine recognized the word.
This all works fine ,but i have a dilemma that what words needed to be
added to the dictionary which i will give to the recognition engine as
dictionary.
If i give words starting with "p" for case pen then words like pendant
,pent etc all will be added to the dictionary.In that case i am not
getting the recognized word as "pen".
Instead i always get other words like "pendant" etc
But if i only add limited words to dictionary like "pe","pen" then for the
same recorded file i got the recognized words as "Pen" only.
Means it clearly depends on the words which we give to the dictionary.
I have conveyed the same to my client.But what they want is that they can
speak wrong words also for a given input words ,so at that time they need
not want to get the accuracy and also get the recognized text.
I have done what i could have done for the issue.But my client needs
something apart from universe.
Do any experts have solution for this here? Any help will be appreciated.
Thanks