QUEST Interleaved Staircase

Background experiment: Online study. Task where participants need to detect a tone from white noise (simple yes/no design). First participants individual thresholds will be configured using a staircase (trying to use the QUEST loop function) - hoping to get the 75% threshold point. Then use the 75%, 50%, 25% and zero (no tone), volume thresholds in the trial later.

I’m using the QUEST staircase at the moment and have tried to set high and low staircases:
|label |startVal|startValSd|pThreshold|method|beta|delta|gamma|grain|range|
|Threshold_Low. |-0.5| 3 |0.75| quantile| 3.5|. 0.01|. 0.5| 0.01 |5|
|Threshold_High |1.5| 3 |0.75| quantile |3.5|. 0.01|. 0.5|. 0.01|. 5|

With this I’m only getting no volume or a loud tone (it isn’t decreasing) - I was wondering if anyone has advice on what parameters would allow me to alter the staircase so it changes the volume until it finds the 75% threshold.

I know I’ll probably have to use some code later to use the 75/50/25% thresholds in the trial- if anyone has any advice about that it’d be much appreciated.

I’m finding a lot of information on how to use quest handlers with code but not the quest function in the builder - so I’m open to go down that route as well.