Late last year Bose presold "prototypes" of a new product it called Noise-Masking Sleepbuds that some 3,000 people picked up at a discount on crowdfunding site Indiegogo. Those early units shipped in April and after a couple of months of "real feedback from real people" Bose has put the Sleepbuds on sale for everyone.

At a press event in New York I got a chance to try out the totally wireless earphones, which retail for $249 and play soothing sounds that are designed to relax you and mask external noises, such as a partner's snoring. The Sleepbuds ship on June 21 in North America and will be available this fall in Asia and Europe. (There's no word yet on international pricing, but I'll add it as soon as I get it. Expect around £250 or AU$400.)

One of the Sleepbuds' key features is their size: They're tiny, weighing a mere 1.3 grams (less than a twentieth of an ounce). By comparison, each AirPods bud weighs 4 grams.

The idea was to create a bud that's so small that it doesn't bother you when you sleep, particularly if you sleep on your side. The earbuds are remarkably comfortable and come with eartips that are designed to block out ambient noise. They're similar to the current StayHear+ tips found on Bose's existing in-ear headphones, but have been slightly modified to allow for a tighter seal.

Going small presented a challenge for powering the earphones. Bose says the Sleepbuds are equipped with a more expensive silver-zinc rechargeable battery that can last two nights on a single charge. A charging case that provides one extra charge is also included.

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Because of their power limitations, the Sleepbuds cannot stream music over Bluetooth -- or play any music at all. The soothing sound files -- they're tiny files -- are stored locally on the earbuds. You pick a sound using the companion iOS or Android app, then the sound plays directly from the buds, it isn't streamed from your phone. (The amount of storage inside the earbud isn't sufficient to store even one full-length, high-quality song, I was told.)

The app initially has 10 sounds to choose from, with more in development that will be added via a firmware upgrade. "These sounds were engineered to maximize masking efficiency and/or facilitate relaxation," Bose says.

As part of the press demo, a Bose rep played city traffic noise, the sounds of "noisy neighbors" and snoring over speakers in a room. He then piped soothing sounds into my ears through the Sleepbuds at about 75 percent volume. I could still faintly hear the intrusive noises, but they were mostly masked out by the pleasant nature sounds I was hearing. I didn't fall asleep during the demo, but it was rather short -- about 5 minutes.

You can program the Sleepbuds to play a soothing sound for a relatively short duration (30 or 60 minutes) or have it play for the whole night. It's worth noting, too, that you can use the app to set an alarm that wakes only you and not your partner. That's a thoughtful feature.

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The Sleepbuds are fairly pricey at $249, but there's apparently some demand for them. They went on sale earlier this month and preorders blew through the company's initial sales forecast in a single day, a Bose rep told me. Like other Bose products, the Sleepbuds have a 30-day money-back guarantee.

I have plenty of nighttime street noise in my New York apartment, so I'll be able to put these guys to the test and determine how effective they really are as soon as I get my hands on a review sample next week. I could use more sleep.