I hate to see threads go unanswered.
"Voice activated" functionality is not easy to achieve in VB6.
There are a number of issues.
Can the sound of the voice be picked up from background noise.
Can a "sound" picked out from background noise be identified as a "voice".
Can anything useful be done to train the computer to recognize voice input as a usable (and discrete) command.
Without third party libraries or controls these things are not a trivial task.
Microsoft does have a Speech Recognition SDK (large, unwieldy and with support for few languages).
The non-DirectX way of recording (inputting) sound is to use the MCI (MS Multimedia) Control, or making direct API calls to winmm.dll.
I know of only one set of code (DirectX4VB tutorial) that shows how record using DirectSound:
The similar "full duplex" version of the code is here