It seems, that "arecord" from "alsa-utils 1.0.28-1" has a bug if setting the duration in the command (-d). After the given duration, the recorded files disappears and multiple files are created every second.
I did not want to downgrade, so I used the command "timeout" in order to substitute the buggy -d flag; e.g. for recording 10 seconds:
timeout 10s arecord [flags except duration flag] [filename]