Notify sound change on actual changes

pactl subscribe get spammed a lot. I think we have to check for value
difference before notifying

scripts/core/sxmo_soundmonitor.sh

@@ -6,15 +6,35 @@
 # shellcheck source=scripts/core/sxmo_common.sh
 . sxmo_common.sh
 
+notify_volume_change() {
+	vol="$(sxmo_audio.sh vol get)"
+
+	if [ "$vol" != "$lastvol" ]; then
+		sxmo_hook_statusbar.sh volume
+		sxmo_audio.sh notify
+	fi
+
+	lastvol="$vol"
+}
+
+notify_mic_volume_change() {
+	micvol="$(sxmo_audio.sh mic volget)"
+
+	if [ "$micvol" != "$lastmicvol" ]; then
+		sxmo_hook_statusbar.sh volume
+		sxmo_audio.sh micnotify
+	fi
+
+	lastmicvol="$micvol"
+}
+
 pactl subscribe | while read -r line; do
 	case "$line" in
 		"Event 'change' on sink "*)
-			sxmo_hook_statusbar.sh volume
-			sxmo_audio.sh notify
+			notify_volume_change
 			;;
 		"Event 'change' on source "*)
-			sxmo_hook_statusbar.sh volume
-			sxmo_audio.sh micnotify
+			notify_mic_volume_change
 			;;
 	esac
 done