The latest trend in wireless headsets are True Wireless Stereo systems (TWS) consisting of two independent units that are charged in their specific charging case. These headsets are typically connected through Bluetooth to a audio source while some contain additional memory for to store music. TWS headsets often contain integrated Ambient Noise Cancellation (ANC) to eliminates unwanted background noise from the received audio and at the same time also minimizes disturbances in the transmitted audio stream picked-up e.g. during voice calls.
Since the devices are also built to be worn over longer periods of time, waiting for the user to say a wake-up word to trigger applications such Siri, Amazon Alexa, Baidu etc. adding new sensors such as a voice helps to reduce the standby power consumption further and extend battery life.
The implementation of a voice pickup coil, who’s functionality is similar to a bone conduction microphone, improves detection of voice spoken by the individual wearing the earbud only.

The charging case uses USB(-C) for charging of its own battery and supplies power to the earbuds for charging. In addition, it can also be used for e.g. firmware updates through a single wire interface to the individual earbuds.