Python code to voice activity detection.This python program can read stream data from your microphone (like USB microphone)

• a buildin microphone or usb microphone on your device, you can use arecord -L to show your audio input devices.
• webrtcvad - pip install webrtcvad
• pyaudio - pip install pyaudio

Make sure your default audio input device is avaliable, and run
python vad.py

This program reads stream audio data from your default audio input device, and decide if a chunk of audio is blank space. It can estimate when you start your sentence and the time you finished.Once you end your conversation, the program write the voice into *.wavfile.