That is not normal, no. The only delay you could adjust is the "Unrecognized Speech Delay" option on the "Recognition" tab of the VoiceAttack options window, however that is by default only set to 250ms, not several seconds (let alone 30).
This could potentially be caused by the speech recognition engine getting hung up trying to recognize what's being said (which can also be exacerbated by a microphone picking up too much background noise).
You could try creating a new speech recognition profile, as outlined in
this topic, in case that has become corrupted.