The Sonic's pivoting ear cups and padded ear cushions work together to create a seal that efficiently blocks outside noise without putting too much pressure on your temples. That said, these aren't active noise-canceling headphones, so you'll still hear ambient noise drifting into your ears if you play your music at a moderate volume. Still, the circumaural (over-ear) design fully engages the drivers in front of your ears, so they perform equally well in an office and a crowded subway station.
Incase builds a 40mm titanium diaphragm driver into each earcup with a 20Hz-20,000Hz frequency response and an impedance of around 32 ohms, but what does that mean for the average consumer? I ran several digital music files through the headphones paired with an Apple iPhone 4S with encoding ranging from 128-320k as well as a few FLAC tracks, and the cans are capable of outstanding high-frequency extension.
Even at high volumes, my copy of Michael Jackson's "Off the Wall" delivered pristine highs with no noticeable sibilance or roll-off, and I was able to hear each vocal snap articulated clearly in the middle. Low-end texture seems to be the litmus test for modern headphones now, and bass lovers and neutralizers alike will be pleased with its depth and lack of distortion.
Finally, the headphones give off an open sense of space that's particularly impressive given their closed-back design. Each instrument takes the listening experience out of the user's head and separates it from the rest of the recorded tracks -- further evidence of this device's acoustic aptitude.
Conclusion Incase proves you don't need to be in business for decades to produce a solid headphone. By crafting new build materials around a cushioned fit with lively performance, the Incase Sonic headphones succeed in producing a near-perfect headphone worthy of your $150 investment.