Audio problem: In the scene where Mike comes home and Carol has ruined his golf club, you hear a door open and close, with a latch/doorknob. She hears it and knows he is home. But he comes in the back door, which was a sliding (glass) door. (00:20:00)
Audio problem: Alice's comment to the girls while handing them their books was obviously dubbed; there's an unusual echo quality in the sound. (00:03:05)
Answer: Much trivia has been written about "The Brady Bunch, " including the various interrelationships and dynamics among the members of the cast. For example, much has been written about why Robert Reed's Mike Brady did not appear in a couple of episodes, including the series finale, due to rancorous creative and artistic differences with series creator, Sherwood Schwartz. However, in contrast, I have never run across any reasons given why a particular child did not appear in specific episodes - only that the episodes were missed. This suggests the causes were likely unexceptional, such as illness, injuries, vacations, or real-life family obligations.
Michael Albert
Although those options ARE possible reasons, it just seems a bit ironic that this happened all in Season 2 ONLY and within a short amount of nearly consecutive episodes. Never happened during the other 5 years of the show at all.