Prices of the models reviewed here range from $25 to $350, and the range in sound quality is equally wide--though sound quality isn't strictly proportional to price. Construction quality and included accessories also vary from one pair of canalphones to the next, though most manufacturers include, at the least, multiple sizes of eartips and some kind of carrying case. Other possible add-ins include cleaning tools, cable extensions, and adaptors for connecting the headphones to home stereos and airplane audio jacks. (None of the models tested here have controls for the iPhone and recent iPods, though some do have inline volume controls.)

I tested the various models using an iPhone 3G playing 256kbps AAC files ripped from CDs; equalization (EQ) and Sound Check features were disabled. The testing was conducted over a period of one month in a variety of settings, both noisy (on airplanes, in commuter trains) and quiet (a basement and a rooftop terrace), from Chicago to Japan. Here's a look, in alphabetical order, at the models I tested.

Right off the bat, the $50 --made by a company, AO Safety, specializing in industrial safety products such as ear-protection equipment--stand out with eye-catching packaging, and bright yellow eartips. In the box are three identical pairs of silicone, triple-flange eartips, along with a fabric carrying bag. The Blockade's eartips are claimed to provide 24dB of noise reduction, and an inline volume-control limits the headphones themselves to 91dB of audio output. The Blockade's construction doesn't seem as solid as most of the other headphones here, but that's not a surprise given the relatively inexpensive price.

The Blockade's tips are soft and comfortable, providing a good seal and the promised noise reduction. On the other hand, if your gut tells you not to expect exceptional sound from a company focused on workplace safety, in this case you'd be right. There's nothing objectionable about the Blockade's sound quality--it's about what someone who's never heard a good set of headphones might expect. But while the midrange frequencies are balanced, they're also muted and distant, and the highs and lows both taper off significantly. Apple's stock earbuds produce better overall sound, just without the Blockade's noise isolation. The $50 price tag is relatively inexpensive for in-ear-canal headphones, but the sound quality isn't as good as several other noise-isolating canalphones priced even lower. For example, the Memorex EB100s tested here cost half as much and have superior bass. And several , such as Sennheiser's and Radius' , also offer better sound in this price range.