After restarting the container, the sound does not work.
root@iobroker:/opt/iobroker# usermod -aG audio iobroker
root@iobroker:/opt/iobroker# chgrp audio /dev/snd
root@iobroker:/opt/iobroker# chmod 777 /dev/audio4
root@iobroker:/opt/iobroker# su - iobroker
iobroker@iobroker:~$ aplay -l
aplay: device_list:274: no soundcards found...
iobroker@iobroker:~$ mplayer /opt/iobroker/iobroker-data/files/sayit.0/tts.userfiles/gong.mp3
MPlayer 1.4 (Debian), built with gcc-10 (C) 2000-2019 MPlayer Team
Playing /opt/iobroker/iobroker-data/files/sayit.0/tts.userfiles/gong.mp3.
libavformat version 58.45.100 (external)
Audio only file format detected.
Load subtitles in /opt/iobroker/iobroker-data/files/sayit.0/tts.userfiles/
==========================================================================
Opening audio decoder: [mpg123] MPEG 1.0/2.0/2.5 layers I, II, III
AUDIO: 44100 Hz, 2 ch, s16le, 192.0 kbit/13.61% (ratio: 24000->176400)
Selected audio codec: [mpg123] afm: mpg123 (MPEG 1.0/2.0/2.5 layers I, II, III)
==========================================================================
[AO_ALSA] alsa-lib: pcm_direct.c:1846:(_snd_pcm_direct_get_slave_ipc_offset) Invalid value for card
[AO_ALSA] Playback open error: No such device
Failed to initialize audio driver 'alsa'
Could not open/initialize audio device -> no sound.
Audio: no sound
Video: no video
iobroker@iobroker:~$ getent group
root:x:0:
daemon:x:1:
bin:x:2:
sys:x:3:
adm:x:4:
tty:x:5:iobroker
disk:x:6:
lp:x:7:
mail:x:8:
news:x:9:
uucp:x:10:
man:x:12:
proxy:x:13:
kmem:x:15:
dialout:x:20:iobroker
fax:x:21:
voice:x:22:
cdrom:x:24:
floppy:x:25:
tape:x:26:
sudo:x:27:
audio:x:29:iobroker,root
dip:x:30:
www-data:x:33:
backup:x:34:
operator:x:37:
list:x:38:
irc:x:39:
src:x:40:
gnats:x:41:
shadow:x:42:
utmp:x:43:
video:x:44:iobroker
sasl:x:45:
plugdev:x:46:
staff:x:50:
games:x:60:
users:x:100:
nogroup:x:65534:
input:x:101:
kvm:x:102:
render:x:103:
iobroker:x:1000: