Most headphones are concerned with blocking ambient noise to better accentuate the music being played. With its new Momentum, X-1 Audio takes the opposite approach, opening the ear up to ambient noise while still aiming to maintain crisp, clear audio. The purpose of this sport-specific design is to keep runners, cyclists and other athletes on busy roads safer and more aware.

The Momentum is the first of X-1's headphones to be deliberately designed to let ambient noise in. While ambient noise isn't ideal for those that want to sit quietly and listen to music, it is a helpful safety ingredient for runners, cyclists and other athletes, helping them to keep aware of their surroundings. Some companies have even developed accessories to allow ambient noise into existing headphones.

While the Momentum lets ambient noise flow, X-1 says that it still provides excellent audio quality thanks to the ear fin, which directs sound straight into the ear canal, enhancing both treble and bass. The ear fin, which comes in three separate sizes with each pair of Momentums, also helps keep the earbud stable inside the ear during intense workouts. The optional silicone earbud cover allows the wearer to vary how much ambient noise comes through.

The Momentum has an Ingress Protection Rating of IP4 and can hold up to sweat, rinsing and inclement weather. An inline mic/remote controls volume and playback, provides for phone answering and call initiation, and offers Siri voice recognition access. Its tangle-free, reflective cord is designed to increase nighttime visibility.

The Momentum is available for US$49.99.

Product page: X-1 Audio