Zhang Wentao, a bank employee in Beijing, recently spent about 2,000 yuan ($285) on a pair of Air-Pods Pro, the latest wireless earbuds from Apple Inc. The buds have since become integral to his daily two-hour subway commute.

"They were not supposed to be a necessity. But once I began wearing the wireless earphones, I didn't want to take them off," Zhang said.

According to him, the earbuds deliver fantastic sound quality, support double-tap to pause music and allow him to take phone calls and talk to Apple's voice-activated digital assistant Siri.

More importantly, the noise canceling technology lets him feel "emotionally peaceful" in crowded subways, Zhang said.

Users like Zhang are helping push the popularity of wireless earbuds. In the third quarter of 2019, hearables alone accounted for almost half the global wearables market, with 40.7 million ear-wear devices shipped from factories, data from market research company International Data Corp showed.

IDC also forecast that as smart hearables get richer functions, more natural device-human interaction experience and stronger computing capabilities, the shipment of earwear devices in China will exceed that of hand-wear devices, including smartwatches.

By 2023, hearables could account for 51.6 percent of China's smart wearables market, which will see annual shipments of nearly 200 million units, IDC added.

"Hearables have become the new go-to product for the wearables market," said Ramon Llamas, research director for IDC's Wearables Team. "This began with multiple vendors removing the headphone jack from their smartphones, driving the move toward wireless headphones.

"It continued with hearables incorporating additional features that either augment or expand the audio experience. Next, hearables have taken on multiple form factors－ranging from truly wireless to over-the-ear headphones－appealing to a broad base of ear-wear user preferences. Finally, prices have come down significantly, with some reaching below $20."

Apple's AirPods series are the most popular category of ear-wear devices. From July to September of 2019, Apple was the top vendor in smart wearables, accounting for 35 percent of the global market. The strong performance is thanks in part to AirPods.

According to a report in Japanese publication Nikkei Asian Review, the AirPods Pro, which became available in October 2019 in China, is so popular that the Apple is doubling Chinese production to 2 million units per month.

Active noise cancellation is a key feature of the AirPods Pro. It uses two microphones (one outward facing and one inward facing) along with advanced software to adapt to each ear for what Apple says is a "uniquely customized, superior noise-canceling experience".

With a built-in transparency mode that can be toggled on, users have the option to listen to music with active noise cancellation turned on while still hearing the ambient environment around them, Apple said.