Harry Potter and the Chamber of Secrets - Lip Reading?
This is just a stupid mistake made by the filmmakers, along with anyone who doesn't realize this. In their first Herbology lesson, they are obviously repotting Mandrakes. Hermione clearly states that anyone who hears the Mandrakes' cry could be killed, even though these are just baby ones that will only knock you out. This is why they need the earmuffs. But, once they put them on, they can still clearly hear Professor Sprout talking. That means that sound does escape into the ears and once a Mandrake is pulled out, everyone should be knocked out cold. But that doesn't happen. Could they have merely lip read Sprout? Actually, they DID hear the Mandrakes beacause they tried to cover their ears at the horrible sound. Is there something I'm missing here?