Audiophiles hifi appreciation thread old and new

do the bose noise cancelling headphone corrupt the sound of the music ?
i guess as they play an inverted sound wave to neutralise the ambient sound extra hertz are going into the headphones or are they on separate circuits ?

Yes, they play polarity-inverted noise to cancel out.

Noise is noise; it shouldn't distort the music. If there's relatively less noise by whatever method then this is a good thing.

You can get cans with good isolation without the need for active circuitry though.