How can i playback sound which collected from mems microphone by nRF52840 DK ?

[Tuhy]

How can i playback sound which collected from mems microphone by nRF52840 DK ? 
And is there possible to stream audio via BLE with 16kHz sampling ?

[Kenneth]

How can i playback sound which collected from mems microphone by nRF52840 DK ? 

Typically you need to use the I2S interface hooked up to an audio codec with I2S interface.

And is there possible to stream audio via BLE with 16kHz sampling ?

Check out: https://www.nordicsemi.com/Products/Wireless/Bluetooth-LE-Audio 

Kenneth