Is there an terminal interface? ( for servers )

No. The audio-recorder program is pretty well modularized but the program is baked and compiled as a GTK3 GUI program.

However it's possible to control the program (the GUI) from command line. The commands are sent over DBus.

Simply start the program with -c or --command argument.

-c, --command argument sends a command to the recorder.
Valid commands are; status,start,stop,pause,show,hide and quit.
The status argument returns; 'not running','on','off' or 'paused'.

Examples:
$ audio-recorder --command start
$ audio-recorder --command hide
$ audio-recorder --command stop

$ audio-recorder --command status
$ audio-recorder --command quit

Please see:
$ audio-recorder --help

This is also valid:
$ audio-recorder --command start,hide

This question was expired because it remained in the 'Open' state without activity for the last 15 days.

Control the recorder from command line with the --command argument, or employ GStreamer directly with the gst-launch tool. See:
http://ubuntuforums.org/showpost.php?p=9589123&postcount=4