Please refer to the following ideas:
1. ANC effectiveness relies on good passive noise cancellation. So please wear the earbuds snugly to enhance noise cancellation;
2. ANC is more effective against low-frequency noise and the effectiveness is less for high-frequency noise. It is suitable for environments like airplanes, trains, and subways, while safety concerns prevent it from filtering high-frequency sounds like car horns and human voices. If you notice reduced noise cancellation, please try adjusting the fit and ensuring the earbuds are worn snugly.