Speech Recognition is cool on paper, but seldom useful in most implementations.
If your IVR choices are simple as "1 for sales, 2 for support" the gain isn't worth the cost.
Where it's practical is when you have many options the customer could choose, for example you have a lot of products the customer could say and be connected to the right destination, or a city to get to the right office.
There should be a number of 3rd party products for this, Avaya has Experience Portal (is it's still called that), I have done some testing with the built-in feature of IPOCC which seems to work fine although that is going end of sale this year.
"Trying is the first step to failure..." - Homer