To use the standard android speech recognition you have to install/deploy the com.google.android.voicesearch apk package.
I don't know if there is an official way to get this. I just googled the apk file.
Just install it by using adb install < apk-file >
Then you should be able to use the voice recognition feature of android on your glass device.
Another way is to use the very cool features of google glass, e.g. to just say "okay glass" to activate the voice recognition.
But therefore you have to root your device and activate this so called lab-feature.
This side is a good starting point for the activation of lab features: glassxe
I have not tried it by myself but I am going to.