Always get ALSA "Debug" written to display

I'm not sure if this is a bug with soundio or my setup, but on Ubuntu 16.10, I always get this output to the terminal:

ALSA lib pcm_dsnoop.c:556:(snd_pcm_dsnoop_open) The dsnoop plugin supports only capture stream
ALSA lib pcm_dsnoop.c:556:(snd_pcm_dsnoop_open) The dsnoop plugin supports only capture stream
ALSA lib pcm_dsnoop.c:556:(snd_pcm_dsnoop_open) The dsnoop plugin supports only capture stream
ALSA lib pcm_dmix.c:1041:(snd_pcm_dmix_open) unable to open slave
ALSA lib pcm_dmix.c:1041:(snd_pcm_dmix_open) unable to open slave
ALSA lib pcm_dmix.c:979:(snd_pcm_dmix_open) The dmix plugin supports only playback stream
ALSA lib pcm_dsnoop.c:556:(snd_pcm_dsnoop_open) The dsnoop plugin supports only capture stream
ALSA lib pcm_dmix.c:979:(snd_pcm_dmix_open) The dmix plugin supports only playback stream
ALSA lib pcm_dsnoop.c:556:(snd_pcm_dsnoop_open) The dsnoop plugin supports only capture stream
ALSA lib pcm_dmix.c:979:(snd_pcm_dmix_open) The dmix plugin supports only playback stream
ALSA lib pcm_dsnoop.c:556:(snd_pcm_dsnoop_open) The dsnoop plugin supports only capture stream

Could someone please advise how to get rid of this?
The problem persists in the sio_ programs included with libsoundio. The program still runs as expected without any problems, just this output is annoying.

Thanks