Apple has unveiled the AirPods 4, marking a significant upgrade with two versions: a standard model priced at $129 and a premium model with Active Noise Cancellation (ANC) for $179. The AirPods 4 feature an open-ear design for the first time with ANC, which performs best against low-frequency noises, and they also include improved sound quality via the new H2 chip. Reviewers noted that while the ANC effectively reduces background noise when music is played, users still hear ambient sounds when it's off. The earbuds also come with a redesigned charging case featuring a USB-C connector and an IP54 rating for durability. In addition, Apple has introduced a hearing aid feature in the AirPods Pro 2, allowing them to amplify sounds for those with mild to moderate hearing impairments, alongside a scientifically-validated hearing test feature. Overall, the AirPods 4 and Pro 2 reflect Apple's ongoing commitment to enhancing audio technology and user experience.