Question

Apparently pulseaudio is using the sound device, although it isn't installed. Where should I start to dig?

speaker-test
lsof /dev/snd/*
fuser -fv /dev/snd/*
apt-get remove pulseaudio

output

speaker-test 1.1.8

Playback device is default
Stream parameters are 48000Hz, S16_LE, 1 channels
Using 16 octaves of pink noise
Playback open error: -16,Device or resource busy
COMMAND    PID USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
alsactl    384 root    4r   CHR  116,0      0t0 9573 /dev/snd/controlC0
alsactl    384 root    5r   CHR 116,32      0t0 9681 /dev/snd/controlC1
pulseaudi 3336 root  mem    CHR 116,56          9680 /dev/snd/pcmC1D0c
pulseaudi 3336 root  mem    CHR 116,17          9571 /dev/snd/pcmC0D1p
pulseaudi 3336 root   17u   CHR  116,0      0t0 9573 /dev/snd/controlC0
pulseaudi 3336 root   18u   CHR 116,17      0t0 9571 /dev/snd/pcmC0D1p
pulseaudi 3336 root   19u   CHR  116,0      0t0 9573 /dev/snd/controlC0
pulseaudi 3336 root   20r   CHR 116,33      0t0 1989 /dev/snd/timer
pulseaudi 3336 root   25u   CHR 116,32      0t0 9681 /dev/snd/controlC1
pulseaudi 3336 root   26u   CHR 116,56      0t0 9680 /dev/snd/pcmC1D0c
pulseaudi 3336 root   27r   CHR 116,33      0t0 1989 /dev/snd/timer
   384  3336   384  3336  3336  3336  3336
..
Package 'pulseaudio' is not installed, so not removed
The following packages were automatically installed and are no longer required:
  rpi.gpio-common vlc-l10n vlc-plugin-notify vlc-plugin-samba
  vlc-plugin-video-splitter vlc-plugin-visualization
Use 'apt autoremove' to remove them.
0 upgraded, 0 newly installed, 0 to remove and 181 not upgraded.