Instruct: Classify Amazon reviews into positive or negative sentiment
Query: a crude approach to noise "canceling"

The only way this device "cancels" noise is by obstructing it via the snug-fitting earphones. Otherwise, acoustically, it is practically functionless. Others have remarked on the awkward placement of the powerbox, which makes the device hard to use standing up. I'll also point out that the switch's on "indicator" consists of a small fingernail-sized painted (not illuminated) red swatch revealed when the switch is engaged. Easy to miss and thus easy to leave the battery on after you remove the phones. Sound quality so-so, a bit muffled but not nasty. I didn't get the buzz that others have mentioned. My advice: pay a bit more for something that works, or a lot less for something that works as poorly as this sorry device does.