While mechanical devices – including flaps, dampers, or acoustic materials – have become commonplace in modern exhaust systems, this unique technology utilizes a dedicated electronic control unit (ECU) to emit sound waves to counter much of the unwanted frequencies (similar to the process of noise-canceling headphones). Of course, the same speaker technology that generates the "white noise" may be used to create new exhaust notes.
The obvious benefits are more appealing exhaust tunes, but it doesn't just stop there. This sound-deadening technology allows automakers to reduced the size of the existing mufflers (saving both weight and cost), and it may add some needed noise to the electric vehicles navigating our roads and highways.
[Source: SAE International]