Raspbian 2018-3-13
https://github.com/shichao-an/soundmeter
sudo apt-get update
sudo apt-get upgrade
sudo apt-get install portaudio19-dev python-dev alsa-utils -y
sudo reboot
pip install soundmeter --allow-all-external --allow-unverified pyaudio
git clone https://github.com/shichao-an/soundmeter.git
cd soundmeter/
sudo python setup.py install
sudo apt-get install ffmpeg
alsamixer
$ python3 soundmeter.py