These are the steps to debug audio on the RadioGlobe project. The commands must be run in the Terminal as pi user.

Firstly we will disable the main program from starting up then remove pulseaudio. We will run a test the streaming class which controls the VLC player. This plays each station for 5 seconds before changing to the next one. Any stations that are not on-line or are not compatible with VLC should be skipped with resulting error output.

Here is a good output from the streaming class playing audio:

pi@raspberrypi:~/RadioGlobe $ python3 streaming.py 
Playing URL, 3, http://81.196.25.70:8000/listen.pls
1892
VLC media player 3.0.11 Vetinari (revision 3.0.11-0-gdc0c5ced72)
[0161c240] main interface error: no suitable interface module
[015a8b58] main libvlc error: interface "globalhotkeys,none" initialization failed
[0161c240] dummy interface: using the dummy interface module...
[7360d3f8] access stream error: HTTP connection failure
[73605328] mpeg4audio demux packetizer: AAC channels: 2 samplerate: 24000

VLC seems to throw all kinds of "errors" even though it plays the audio

Here is Alsa playing the stream:

pi@raspberrypi:~ $ ps aux | grep alsa
root       385  0.0  0.4  11768  4576 ?        SNs  13:02   0:00 /usr/sbin/alsactl -E HOME=/run/alsa -s -n 19 -c rdaemon
pi        1892 24.6  1.8  96344 17260 pts/0    Sl+  13:19   0:00 /usr/bin/vlc -I dummy --aout alsa http://81.196.25.70:8000/listen.pls
pi        1910  0.0  0.0   7348   512 pts/1    R+   13:19   0:00 grep --color=auto alsa


Now to run the test

1. Disable RadioGlobe service from starting automatically
pi@raspberrypi:~ $ systemctl disable radioglobe.service

2. Remove pulseaudio
pi@raspberrypi:~ $ sudo apt remove pulseaudio

3. Reboot

4. Run streaming class test ( Ctrl + c to exit )
pi@raspberrypi:~/RadioGlobe $ python3 streaming.py

The output should be similar to above and audio should play. Once this test is successful the RadioGlobe app can be re-enabled on startup. 
5. Re-enable RadioGlobe
pi@raspberrypi:~ $ systemctl enable radioglobe.service

It seems that even if the audio output is set to "pulse" in streaming.py, VLC will fall-back to Alsa and play the stream with the following error message:

[01fc8538] vlcpulse audio output error: PulseAudio server connection failure: Connection refused