또 노면소음은 약 0.009초만에 실내로 전달되는 데다 불규칙적이어서 이를 측정하고 분석한 뒤 상쇄 음파를 즉시 발생시켜 소음을 줄이는 것이 기술적으로 어려웠다.
In addition, road noise is transmitted indoors in about 0.009 seconds and is irregular, so it was technically challenging to reduce noise by immediately generating offset sound waves after measuring and analyzing it.