duration of stimuli synced

[bisserai]

Hi FF team,

It's me again and with the same study, but facing another problem. I would like to present a fixation cross which stays on while an audio stimulus plays and once the audio finishes i'd like to have the fixation cross disappear and the response buttons appear. Everything is working except i can't get the end of the audio to trigger the fixation cross to leave the screen. I've tried using the group function, where my audios are defined like so:
{
  "type": "audio",
  "content": "V1L.wav",
  "visible": false,
  "delay": 1.5,
  "barrier": true,
  "group": "group1"
}

and my fixation cross defined like so:
{
  "type": "text",
  "content": "+",
  "size": "150px",
  "alignment": "center",
  "duration": "%sgroup:group1"
}

The trial template is defined like so:
"audioP": {
    "type": "basic",
    "stimuli": [["fixx","V1L"], ["fixx","J1R"], ["fixx","M1R"]],
    "responses" : ["v1","j1", "m1"],
    "submission_point": false,
    "stimulus_pattern": {"order": "random", "attribute": null, "pre_shuffle": false}
  },  


From a previous study where we used the group function i remember the audio had to have barrier set to false, so i also tried that, but it didn't have the desired effect so i put it back to true, since i need that to delay the appearance of my response buttons. I played around with the duration characteristic, but i didn't seem to get anything useful out of it...

Your advice will be much appreciated!

Best,
bissera