I'm trying to come up with an implicit spell checker that will use the mappings of input words to some kind of more general phonetic representation to account for typos that might occur, basically for a search bar that will automatically correct your spelling to a degree. Two things that I've been looking into are metaphone, nysiis and soundex, but I don't really know which would be better for this application.
I would like there to be preferentially more matches than less matches, and I would like the matching to be a bit more general and so for that reason I was thinking of going with soundex which seems to be a more approximate mapping than the original metaphone, but I don't really know how large the difference in vagueness is. I know that nysiis is pretty similar to soundex, but I don't have a good idea of how similar they are, or how nysiis compares to metaphone.
I am also looking for the solution that is quickest to execute. I know that these phonetic mappers are usually pretty quick, but I'm not sure which would be fastest, considering I would like to be able to check spelling without an increase in search time, speed is a consideration. Thoughts?