<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by Andrew Webber:
I agree the bulky design is needed for passive noise reduction, but wouldn't active noise reduction be as effective in a walkman-style or in-the-ear set?</font>
I suspect the Bose actually have superior noise reduction circuitry. The better passive noise reduction not only helps block out external noise, but also reduces the amount of noise reduction "stuff" that leaks out into the cabin.