How do I make a sound appear on the first trial only?

Builder
1

In the experiment I’m building, the subject sees an image (there are 20 total images) for 20 seconds and after that has to answer a question. I’d like to play a sound while he’s watching the first image, but not the others. I would create a two different routines and use a loop for the remaining 19 but I’d like to have all 20 in the same loop because I need them to all come randomized from the same list. How can I achieve this?

2

You could have a start condition for the sound component of trials.thisN == 0

Does the routine normally end on participant interaction? If it has a timeout, you might need to add that to Routine Settings to account for the sound component never ending (when it doesn’t start).

3

The start condition works, thank you! My problem is that (I forgot to mention it in my post, sorry) the sound should play 10 seconds after the image started. If I set the condition, the sound starts instantly. What can I do?

4

When does the image start?

5

0.5 seconds (before that i have a fixation cross)

6

Try this

Begin Routine

playSound = False

Each Frame

if playSound == False and t >= 10.5 and trials.thisN == 0:
     playSound = True

Then set the sound component to start on condition playSound

7

Seems to work, thank you so much!