Here is a review left by a customer on a product. Would you say he was satisfied or dissatisfied?
Title: Not noise cancelling - noise reducing. Amazon has mislabeled this product.
Review: That is not just a symantic difference. Noise cancelling implies active circuitry to detect specific frequencies and emit an inverse signal to counteract them. These are not even labeled as noise cancelling on the box but as noise reducing. That means that the noise reduction is completely passive. Amazon has mislabeled this product and it was not what I expected. They are, however, very good noise reducing earmuffs. A bit bulky, though.
