There are two kinds of noise-canceling earphones: in-canal earphones that use passive noise reduction -- a physical barrier to block outside noise -- and earphones with active noise cancellation, which generates white noise to negate unwanted sounds. (ConsumerSearch has a separate report on headphones, which includes noise-canceling models.) Most in-ear headphones already discussed in this report passively block sound to some degree, some being more noise isolation than others. There are, however, a few earphones that include noise cancellation technology meant to block out even more ambient sounds.
Panasonic's RP-HC55 (*Est. $50) earphones get the best reviewer responses. Battery life is very good, though sound quality is average. Australia's Choice and New Zealand's Consumer magazines both measure active noise cancelation precisely, finding it far superior on these earphones than on other in-ear models, though it falls short of that found on full-size headphones. Britain's Which? recommends the Panasonic RP-HC55 earphones for their impressive noise reduction and good sound quality, though they can't quite bring out the highest highs and lowest lows. The noise cancellation unit is heavy at 1.3 ounces and needs to be clipped to a shirt to avoid pulling out the earpieces. Owners are also disappointed that these earphones don't work without noise cancellation on, which means always making sure there's a working AAA battery in the compartment.
Audio-Technica also offers noise-cancellation technology with its ATH-ANC23 (*Est. $80) earphones. Jeremy Horwitz at iLounge.com gives them a high recommendation, and they're an Editors' Choice at DigitalTrends.com. Reviewers say music comes out clearly and smoothly, though Caleb Denison at DigitalTrends.com thinks highs can come off a little weak on some tracks. Unlike the Panasonic RP-HC55, the ATH-ANC23 earphones do work with noise cancellation off or a low battery in the unit. Reviewers and owners think these earphones are a great value.
The AKG K390 NC (*Est. $200) are an option for those looking for high-end noise cancellation earphones. There's good clarity from these earphones and the detail is there, though there is some muffling in all sonic ranges when noise cancellation is turned on. This unit also works when noise cancellation is turned off. There's a microphone and remote, but make sure your device is compatible (iPhone, iPhone 3G and some Blackberry models). Aside from cost, the biggest downside is that the AKG earphones' noise-canceling unit is bulky at 1.7 ounces.