Apple delayed its wireless AirPods in October with no reason why, or word when they will released to market. Weeks later, Apple hasn't provided an update on the delay and lists AirPods as "coming soon" to its online store.

According to the Wall Street Journal's sources, AirPods' delay is technical and due to Apple working to ensure both ear pieces receive a signal simultaneously to reduce connection drops.

"Apple must ensure that both earpieces receive audio at the same time to avoid distortion," a person familiar with their development told the Journal. The same person said Apple is working to "resolve what happens when a user loses one of the earpieces or the battery dies."

AirPods rely on a proprietary Apple chip communicating with both earbuds to stream audio. Other wireless headphones send Bluetooth audio to one earbud and beam it over to the other.

Costing $159, the AirPods compliment the iPhone 7 that doesn't feature a headphone jack.

"The early response to AirPods has been incredible. We don't believe in shipping a product before it's ready, and we need a little more time before AirPods are ready for our customers," Apple said in an October statement.

Sources tell blogger John Gruber that Apple is having issues manufacturing AirPods at scale.

In November, Barclays analysts said in a research note AirPods should start production in December, but ordered units are small at 10 million to 15 million during production start.

Taiwan-based Economic Daily News reported that a supplier expected to begin "shipping AirPods in January 2017."

Source: ZDNet