Drake & Josh, iCarly, and every Dan show that followed were different from Hannah Montana, Wizards of Waverly Place, and The Suite Life in one key way: they were multi-camera sitcoms, but they weren’t filmed in front of a live studio audience.
From what I’ve heard, it only happened once—and never again—during the filming of the original & unaired Drake & Josh pilot.
Before Drake & Josh, shows Schneider were a part of regularly incorporated live audiences, including The Amanda Show, Kenan & Kel, and All That.
But after experimenting with a live audience for scenes of the unaired Drake & Josh pilot, they never returned to it.