I think sfg49r means he doesn't have the shortcut / icon to press (I didn't on one of my Razrs). Search the forum for:
Missing the Voice Search button? Here's the fix
I downloaded the recommended app and had "Voice Search" back in minutes.
I see--but my point was that a shortcut isn't necessary, since long-pressing the hard search button is a built-in shortcut. If that's not working, I would wonder if there's something wrong with the Voice Search function itself. Voice Search is a stock app, so it can't be uninstalled--that's why you can't install it from Google Play. The only thing you could do there would be to update it, if an update were available.