Active sound design is when people use special tools and techniques to create sounds that you can hear in things like movies, video games, and TV shows.
Let's imagine you're watching a movie about aliens. When the aliens are walking around, you can hear their footsteps. But, how did the sound designers make those footsteps sound so real?
Well, sometimes they use special microphones to record sounds of things like shoes hitting the ground. They might even record sounds of people walking in different ways to get even more sounds to work with.
Then, they use a computer program to edit the sounds and make them sound even better. They can change the volume, add special effects, and even change the sound completely if they need to.
The sound designers work hard to make sure the sounds match what's happening on the screen. For example, if a car is driving really fast, they might make the sound louder and add more engine noises to make it feel more intense.
Overall, active sound design is all about creating sounds that make what you're watching or playing feel more real and exciting!