Yes its possible to transmit a good quality 8bit raw sound through Arduino IDE and Nodemcu. Y
I did it my self and I was able to achive
1) Transmit clear voice from a microphone connected to ESP8266 to a remote machine and could listen the same on headphones.
2) Transmit clear voice from a microphone connected to my laptop to ESP8266 and could listen the same on headphones connected to ESP8266.
Additionally, a low pass filter and an audio amplifier circuit are required (can make your own with few Resistor,Capasitor and Transistors)
You can use the code from
https://github.com/nodemcu/nodemcu-firm ... etwork.lua