unexpected interval between auditory stimuli

I am trying to make a kind of oddball task.
I made 5 types of auditory stimuli (duration:1s for each, sizes:about 90kb for each).
I run these stimuli 300 times, and make participants to respond with keyboard.
Attached file is this experiment.

When I tried this task, unexpected time intervals between auditory stimuli appear many times (sometimes 5s or longer).
And sometimes, I hear this auditory stimuli are played quickly than expected, and two stimuli overlap with each other.

I saved auditory stimuli on the desktop of my note-PC, since I read the USB device driver will make unexpected delay on this forum.
My note-PC is dynabook NX/78JWH, has extra 45.5GB in C drive.
I am using superlab 4.5.2…

Could you help me to find out what causes this trouble, and what can I do for it.

distraction oddball.sl4 (15.6 KB)

The delay can be caused by a variety of different issues. Can you please post your experiment again? This time as an Experiment Package, which is found under the File menu within SuperLab? I cannot run the experiment that was posted because none of the files were included.

Thank you so much for your help.
I posted the file as an Experiment Package as you recommended.

distraction oddball.zip (116 KB)

Since we don’t have the data file we don’t know exactly what to look for. We’ve noted the following:

  1. The first 12 “700Hz” trials are set so the correct response in none “Participant must not respond”. Whereas the rest are set to “Any response is correct”.

  2. Events within the trial are being randomized. Are you sure you want to do this? Most people need to randomize the trials within the block.

Thank you so much for your help.
I am sorry for not having posted my audio stimuli. Now I posted them.

In my experiment, there are two different length stimuli, and I want participants to respond to longer one while ignoring shorter one.
First tweleve 700Hz stimuli are shorter ones, so participants should not respond to that, while latter tweleve 700Hz stimuli are longer ones, and participants should detect that and respond that.
Are there any possibilities that this response definition relate to the delay?

Also, every single stimulus consists one event and I need each of them run randomly.
Does this randomization cause unexpected delays?

500Hz, 200ms,1s.wav (86.2 KB)

700Hz, 100ms,1s.wav (86.2 KB)

700Hz, 200ms,1s.wav (86.2 KB)

900Hz, 100ms, 1s.wav (86.2 KB)

900Hz, 200ms, 1s.wav (86.2 KB)

We ran your experiment a few times and noticed a slight delay in-between trials, but not all time. Try going to Experiment, Options, then Memory Management. Select “Load them all before running the experiment” to see if it helps with the delay.

Thank you for your proposal.

I tried to run the experiment after I selected “Load them all before running the experiment”.
I think the number of unexpected time intervals decreased. Thank you.
But I am afraid there are still some slight time intervals, which I can detect and may have some effects on the result of the experiments.
If you have any other ideas, I would appreciate if you could tell me.

Can you try changing your settings to “Stop audio: when the event ends” instead of “allow audio to continue playing until it ends on its own”? This may help with the time intervals.

Thank you so much for your kind help.
I think it helped me to decrease unexpected intervals. Thank you again.