From Wikipedia:
The Kármán line lies at an altitude of 100 kilometres (62 mi) above the Earth's sea level, and is commonly used to define the boundary between the Earth's atmosphere and outer space.
That's not space. Though it's an amazing feat nonetheless.
It's not an artificial boundary. It's the approximate maximum altitude at which winged vehicles have to move faster than the orbital velocity (at that altitude) in order to attain lift (where lift is depending on the pressure at that altitude). A wing moving below orbital velocity and above that altitude will not get lift at any angle of attack, just drag.
I was waiting for the camera to stop picking up sound the whole time. It got really squeaky and full of static towards the peak but it never seemed to happen.
Sound vibrations will still be picked up in a vacuum in this case. Vibrations through the rocket body will be transmitted to the camera body (direct contact) which will then be transmitted to the microphone (again, direct contact). According to Wikipedia[1], 90% of the Earth's atmosphere, by mass, is at an altitude of 52,000 ft or lower.
From Wikipedia: The Kármán line lies at an altitude of 100 kilometres (62 mi) above the Earth's sea level, and is commonly used to define the boundary between the Earth's atmosphere and outer space.
That's not space. Though it's an amazing feat nonetheless.