We might finally know why Apple delayed its futuristic wireless earbuds

When Apple announced the headphone jack-less iPhone 7 this past September, it also launched the AirPods, a pair of completely wireless set of earbuds similar to smaller-scale offerings like the Bragi Dash and Samsung Gear IconX.

The little white earphones were expected to go on sale sometime in October, for $159. We're now well into December, however, and they're still nowhere to be seen.

Apple formally delayed the earbuds in October, saying it needed "a little more time before AirPods are ready for customers," but it's been vague in explaining what exactly the hang-up is.

According to a new report from The Wall Street Journal, though, the issue sounds mostly technical. Citing a "person familiar with the development of the AirPod[s]," the report suggests Apple is struggling to ensure that both AirPods receive a Bluetooth signal simultaneously, something that would help them avoid sudden connection dropouts.

It still isn't clear when exactly Apple will release the AirPods to the public. A Barclays analyst said in November that Apple will start AirPods production on a limited basis sometime in December, but Apple hasn't provided any update since.

If Apple is having trouble keeping AirPods' connection consistent, it wouldn't be a surprise - most other truly wireless earbuds on the market today suffer from similar connection problems.

With the current Bluetooth protocol, wireless audio cannot be streamed to two separate devices simultaneously. As a result, wireless earphone makers have thrown various solutions to keep two untethered earbuds in sync. The likes of Bragi and Doppler Labs use a tech called Near-Field Magnetic Induction (NFMI), some have deployed the Bluetooth low-energy protocol (formerly BLE), while others have used different technologies.

Usually, all of these involve sending an audio signal to one earbud, which then quickly relays the signal to the other earbud. This can work, but, as the choppy performance of most of truly wireless headphones have shown, it's difficult to make reliable. That's because it still leaves room for foreign objects - such as your head - to interfere with the signal.

As Business Insider reported in October, Bluetooth SIG, the organization that oversees the development of Bluetooth, is working on an update that would allow devices to send audio streams to multiple devices at once using the Bluetooth low-energy protocol, but that isn't scheduled to arrive until sometime next year. When it comes, the hope is that it'll reduce many of the technical hang-ups truly wireless earbuds face today. Apple currently has a spot on the Bluetooth SIG's board of directors.

As the WSJ notes, though, Apple says each AirPod earpiece can receive an independent signal. This is likely due to the proprietary, low-energy W1 chip that's built inside the device (and other Beats headphones). If the company is still having trouble getting those signals to each earbud at the same time, however, that suggests Apple's attempt to get ahead of the open Bluetooth standard hasn't gone as smoothly as hoped.