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-canceling headphones are not perfect. They're usually most effective for ambient noise at low frequencies. Experts note, however, that they can effectively reduce overall noise by as much as 80 decibels, which should be enough to reduce irritating interference from loud jet engines on an average airplane flight.