And the envelope, please?

Where to begin... I teach physics. Lots of these topics just aren't intuitive. In fact, many are absolutely counter-intuitive and bizarre. During a sound investigation, the kids had to strike a tuning fork and listen to the sound produced. I made sure they knew how to strike a tuning fork; NEVER on a hard surface, always use the heel of the hand. After about 5 minutes of hearing the kids banging tuning forks and giggling at the sounds, I noticed one kid sitting all puzzled and not participating. I went over to her and asked what was what. She said she couldn't hear anything. Now, I was thinking, "Damn! This kid has a hearing problem I didn't know about and this sound activity is making her feel bad!" I asked what she was doing and if I could help explain anything. She repeated that she WAS hitting the tuning fork on her palm and it just wasn't making any sounds. I asked, as usual, to see what she did so I could troubleshoot. She struck the tuning fork on the heal of her hand and raised her palm to her ear! She thought her hand was supposed to make the sound... sigh...
On to #8!