Who Mourns for Adonais? - S2-E2
Audio problem: At the temple, as Kirk goes to call the ship, he flips the communicator to open it, as he usually does. However, he has to flip it twice to get it to open, but the sound of the channel opening is heard from the second he starts.
Audio problem: About a minute or two into the episode, Captain Kirk says "That's incredible" but his mouth doesn't match the words.
Audio problem: As Commodore Stocker freezes up on the bridge, before the cut to sick bay, the bridge is shaken by a Romulan blast, but the sound is absent.
The Ultimate Computer - S2-E24
Audio problem: After trying to change course, Sulu calls Kirk. Kirk says "Kirk here", and then you hear the click of the comm button being hit.
Answer: After causing Norman to overload, all of the other androids shut down. The same could be said for the androids on the Enterprise.