Due to this high prevalence, vertebral artery hypoplasia (VAH) has not yet been considered an independent risk factor for ischemic stroke [1,2].
How to use your own headphones on Americanâs new 777-300ER. Passengers traveling in First and Business Class on Americanâs new 777-300ER are provided with Bose QuietComfort 15 Acoustic Noise Canceling headphones to use during the flight.
Noise-cancelling headphones are battery-powered headphones that actively cancel out the ambient noise surrounding a listener. The most common use for them is during plane journeys. While sound-isolating earphones will block out chatter, it won't get rid of the noise of a jet engine. Noise-cancelling headphones will. Put simply, they work by using tiny microphones that listen to the noise surrounding the listener.