Bose's open earbuds are built for runners. Here's the trade you're making.

CNN Underscored’s mid-October launches column included Bose’s two new open-ear models — the Sport Open Earbuds and the second-generation Ultra Open Earbuds — which Forbes’s Mark Sparrow had covered at their September announcement. The prices are $199 for the Sport and $299 for the Ultra, unchanged from the first-generation Ultra. Bose’s own press release put both on sale October 1; Forbes reported the Sport’s availability as October 15. Either way, they’re in shops now, just as the autumn marathon season peaks.

The design is the point: these clip onto the outside of the ear and leave the canal open. You hear your music and you hear the car.

Why open is right for the road

Most earbuds are sold on isolation: seal the ear, cancel the noise, disappear into the playlist. On a treadmill that’s a feature. On a road at 6 a.m. it’s a hazard. Runners have been improvising around this for years — one bud in, bone-conduction headbands, volume low enough to be pointless. A properly engineered open earbud is the honest solution, and it’s good that a company with Bose’s audio reputation is competing on it rather than leaving the category to the sports specialists.

The Sport at $199 is the model aimed squarely at this use; the Ultra at $299 is the lifestyle version of the same idea, for people who want to stay in the conversation at a desk or on a train.

What you give up

Be clear-eyed about the trade. Open earbuds have no noise cancelling, by definition, and they leak sound a little in both directions. Bass is physically harder to deliver without a seal. In a loud environment — a gym with a sound system, a busy subway — you’ll hear the environment more than the music. If you want a sealed, cancelling earbud for flights and commutes, this isn’t a replacement; it’s a second pair.

Fit is the other variable. A clip that sits on the outside of the ear has to stay put through sweat and footstrike, and that’s something to test rather than trust — which is the strongest argument for buying from a retailer with easy returns.

Who should buy which

Run outside more than inside: the Sport, and accept that it will be your running earbud rather than your only earbud. Want one pair for the office, the walk and the occasional jog: the Ultra, and accept the extra $100 is for versatility rather than sound. Mostly on a treadmill or in a gym: neither, probably; a sealed sports earbud will serve you better there.

The takeaway

Open-ear audio used to mean “worse sound for safety’s sake.” Bose putting its name on the category is a sign that it’s become “different sound for a different job.” For road runners that job is staying alive at junctions, and $199 for a well-made pair that does it without compromise is a fair price. Just don’t expect them to make the subway go quiet.