Review | These swimming headphones use bone conduction to send sound waves to your inner ear: AfterShokz Xtrainerz review

The AfterShokz Xtrainerz (pronounced “cross trainers”) are a headband-style pair of earphones that are completely waterproof, ideal for those who want to listen to music while swimming those endless laps. The headphones don’t actually go anywhere near your ear canals. Bone conduction is something AfterShokz has been pioneering for a few years, most notably on its Titanium and Trekz Air headphones (the latter a favourite with runners, recently updated and renamed Aeropex). Both look much like the Xtrainerz. What they all have in common is that their speakers sit outside the ear. Instead of using tips to fit snugly into the ear and cut out any extraneous noise, headphones equipped with bone conduction transducers sit on the outside of the ear and vibrate to send sound through your temporal bones directly to your inner ear. I put the Xtrainerz to the test to see how well they worked in practice. Design Like all previous AfterShokz bone conduction headphones, the Xtrainerz have an open design. They weigh just 28g and are IP68-certified, meaning they are able to withstand complete submersion in up to two metres of water. In the box is a small silicone carry case that is itself waterproof, as well as a set of earplugs and a USB charging cradle. The latter magnetically connects to the AfterShokz, but it’s a proprietary design. It’s something else not to lose, but it makes sense on this uniquely watertight product. Software Music files have to be physically loaded on to the headset in MP3, WMA, AAC, FLAC or WAV formats. The process is easy – plug the cradle into a computer and it pops up as a portable storage device. It’s then just drag and drop – there aren’t even any folders. It all recalls an almost bygone era. After all, how many people have actual MP3 music files in this age of streaming? If you only have a few old MP3s knocking around it’s no great problem because all you need is something to keep you occupied while you swim. Besides, the Xtrainerz only stores 4GB of music. That’s about 1,200 songs, which is about right considering you’re not going to want to be manually tinkering with the contents too often. The best option is to fill it and forget it. Performance and sound quality The Xtrainerz are extremely comfortable since they sit outside of the ear; the earpieces are actually just small speakers. However, when used on dry land against background or ambient urban noise they’re just too quiet, even at full volume. The headphones stay on the head really well when swimming, their flexible silicone headband design easily rigid enough to stay still during a powerful front stroke. Don’t consider diving or jumping into the water, but anything else that happens in the pool isn’t going to affect the device’s stability. The soundstage the headphones create is surprisingly sassy and consistent. However, sound quality depends on the included earplugs, which block the sound of splashes and general din in a swimming pool. With the earplugs in place, the sound quality in the water is excellent. In fact, the highest volume is way too loud underwater, where the headphones really excel. Remove the earplugs and the sound quality remains strong when ears are underwater, but reduces dramatically when they’re above it. The 183mAh battery inside the device is puny, but size is understandably at an absolute premium. The six hours they last for means you can leave them in your pool bag for the week, so in practice the small battery is not an issue. Conclusion The Xtrainerz are a unique and high-performing product that you can pretty much ignore when wearing in a pool. If you swim a lot, or just as likely, you don’t swim at all because it seems so dull, they will suit you well. The manual transfer of music files to the Xtrainerz gets a little tiresome, but aside from a weekly recharge and a top-up of tunes, it’s surprisingly undemanding. Sound quality is impressive and consistent as long as those earplugs are worn. That’s slightly annoying if you don’t already swim with earplugs, but it’s really hard to fault the performance of the Xtrainerz for their core use. My main concern is that they lack an optional Bluetooth mode. Being able to wirelessly connect to a phone when out of the pool would make them a much more attractive product, particularly for running and the gym, where swimmers may find themselves before hitting the pool. Being unable to do the relatively simple task of stream music from a phone forces athletes to change headsets between activities. That makes the one-off Xtrainerz looking like a super-niche product and a real indulgence, though as a technical achievement, they’re incredibly impressive. Price: US$150

Review | These swimming headphones use bone conduction to send sound waves to your inner ear: AfterShokz Xtrainerz review

The AfterShokz Xtrainerz bone-conduction underwater headphones send sound through your temporal bones directly to your inner ear Slim, comfortable and with surprisingly good sound, the headphones excel underwater, though are far too quiet for dry land

The AfterShokz Xtrainerz bone-conduction underwater headphones send sound through your temporal bones directly to your inner ear

Slim, comfortable and with surprisingly good sound, the headphones excel underwater, though are far too quiet for dry land