They're not even active noise cancelling. They work just as well with no battery. They're not "dead silent" but I can be making no noise and you have to yell to get my attention.
As an added bonus they're reflective, not that that in any way makes up for the massive reduction in situational awareness you are causing by purposefully handicapping your hearing ability while in/around traffic.
Edit: Did you edit your comment or was it someone else who mentioned wanting to listen to audiobooks while walking down the street?
No. I know of dozen better solutions for people who want to listen to music in high-noise environments, starting with the cheap-and-good (Mee M6Pro, $50, plus ear-safety isolators, $10) and ranging through moderately priced and good (Sennheiser HD280Pro, $100, Beyerdynamic DT770, $150) and going on up in price but not necessarily isolation.
I’ve been very happy with the Monoprice “SonicSolace” ones. Haven’t done a side-by-side comparison, but I’ve found them perfectly good for airplane use, and they’re definitely cheaper.
I bought the Cowin E7's from Amazon for $60. I've tested them and the noise-cancelling is every bit as good. The audio sounds just as good too, but I don't pretend to be an audiophile and the noise-cancelling is what is important to me.
Came to say the same thing. I'm not exactly an audiophile, but being able to listen to an audio book at less than 110% volume while walking next to a busy road is fantastic.