The phrase "active sound" is correct and usable in written English.
You could use it to describe the sound of a group of people going about their business, such as the "active sound of students walking around the campus between classes."
They call it Active Sound Design.
So why is Active Sound Design so surprising?
In fact, BMW already do this inside the car for you, with their "active sound design".
Credit the so-called Active Sound Symposer, essentially a sound tube that modulates the quantity of low-frequency rumblings that enter the cabin, depending on vehicle speed.
Already the Renault Zoe, an electric car, has a sound generator for use at low speeds, and the Lexus IS 300h hybrid has an "active sound control" system designed to give its four-cylinder engine the sound of a V6, even when cruising on electric power.
This paper addresses active sound transmission control based on structural sensors and actuators.
This paper develops an active sound-quality control (ASQC) system based on the active noise equalization (ANE) technique, and optimizes it with the filtered-error least mean square (FELMS) algorithm and normalized reference signal generator.
For that "rumble in the jungle" sensation, Clark Synthesis introduced a more affordable line of its Tactile Sound, active-sound transducers ($99 and up) — low bass speakers discreetly mounted within seats or under floors to scare the bejabbers out of you at dramatic moments.
Active sentences sound more confident than passive sentences, especially when you use the word "I".
His abdomen was soft and non-distended, tender to palpation in the right lower quadrant with rebound and guarding; normal active bowel sounds were present.
