Hmmm, seems the mixer control "Auto-Mute Mode" has been removed.
[doktor5000@Mageia4 ~]$ amixer -c 0 controls
numid=35,iface=CARD,name='Headphone Jack'
numid=33,iface=CARD,name='Internal Mic Phantom Jack'
numid=34,iface=CARD,name='Line Jack'
numid=32,iface=CARD,name='Mic Jack'
numid=39,iface=CARD,name='SPDIF Phantom Jack'
numid=38,iface=CARD,name='Speaker CLFE Phantom Jack'
numid=36,iface=CARD,name='Speaker Front Phantom Jack'
numid=37,iface=CARD,name='Speaker Surround Phantom Jack'
numid=31,iface=MIXER,name='Master Playback Switch'
numid=30,iface=MIXER,name='Master Playback Volume'
numid=3,iface=MIXER,name='Headphone Playback Switch'
numid=2,iface=MIXER,name='Headphone Playback Volume'
numid=45,iface=MIXER,name='PCM Playback Volume'
numid=5,iface=MIXER,name='Surround Playback Switch'
numid=4,iface=MIXER,name='Surround Playback Volume'
numid=8,iface=MIXER,name='Center Playback Switch'
numid=6,iface=MIXER,name='Center Playback Volume'
numid=9,iface=MIXER,name='LFE Playback Switch'
numid=7,iface=MIXER,name='LFE Playback Volume'
numid=24,iface=MIXER,name='Line Boost Volume'
numid=18,iface=MIXER,name='Line Playback Switch'
numid=17,iface=MIXER,name='Line Playback Volume'
numid=23,iface=MIXER,name='Mic Boost Volume'
numid=16,iface=MIXER,name='Mic Playback Switch'
numid=15,iface=MIXER,name='Mic Playback Volume'
numid=20,iface=MIXER,name='Capture Source'
numid=22,iface=MIXER,name='Capture Switch'
numid=21,iface=MIXER,name='Capture Volume'
numid=29,iface=MIXER,name='IEC958 Default PCM Playback Switch'
numid=25,iface=MIXER,name='IEC958 Playback Con Mask'
numid=26,iface=MIXER,name='IEC958 Playback Pro Mask'
numid=27,iface=MIXER,name='IEC958 Playback Default'
numid=28,iface=MIXER,name='IEC958 Playback Switch'
numid=19,iface=MIXER,name='Auto-Mute Mode'
numid=41,iface=MIXER,name='Beep Playback Switch'
numid=40,iface=MIXER,name='Beep Playback Volume'
numid=1,iface=MIXER,name='Channel Mode'
numid=14,iface=MIXER,name='Speaker CLFE Playback Switch'
numid=11,iface=MIXER,name='Speaker Front Playback Switch'
numid=10,iface=MIXER,name='Speaker Front Playback Volume'
numid=13,iface=MIXER,name='Speaker Surround Playback Switch'
numid=12,iface=MIXER,name='Speaker Surround Playback Volume'
numid=43,iface=PCM,name='Capture Channel Map'
numid=42,iface=PCM,name='Playback Channel Map'
numid=44,iface=PCM,name='Playback Channel Map',device=1