Millisecond Forums

controlling volume levels

https://forums.millisecond.com/Topic12902.aspx

By rburtonaus - 4/4/2014

I am trying to give subjects the opportunity to set the volume to a comfortable level at the start of each session.
I have set volume as a value as follows:
<values>
/Vol=-5000
</values>
and 
<sound TestSound>
/items = ("TestSound.wav")
/volume = (values.vol)
</sound>

I have tried a variety of ways of setting the variable using blocks and trials but nothing seems to work.
Here is an example:

<trial VolChange>
/inputdevice = mouse
/stimulustimes = [0 = VolumeUp, VolumeDown, Continue; 1000 = TestSound]
/validresponse = (VolumeUp, VolumeDown, Continue)
/correctresponse = (Continue)
</trial>

<block AdjustVol>
/trials = [1-50 = noreplace(VolChange)]
/branch = [if(trial.volchange.response==VolumeUp) values.vol+= 1000]
/branch = [if(trial.volchange.response==VolumeDown) values.vol-= 1000]
/branch = [if(block.adjustvol.correctstreak>0) block.600block]
</block>

Even the last branch (correct streak) doesn't work for me.

I would very much appreciate advice.
By Dave - 4/4/2014

There are various syntax errors in your code. Particularly missing double-quotes and inappropriate use of /branch (you want /ontrialend, not /branch):

<values>
/ myvolume = -5000
</values>

<block myblock>
/ trials = [1=mytrial]
</block>

<trial mytrial>
/ stimulusframes = [1=mysound, mytext, up, down, stop]
/ inputdevice = mouse
/ validresponse = (up, down, stop)
/ ontrialend = [if (trial.mytrial.response=="down" && values.myvolume > -10000) values.myvolume -= 500]
/ ontrialend = [if (trial.mytrial.response=="up" && values.myvolume < 0) values.myvolume += 500]
/ branch = [if (trial.mytrial.response != "stop") trial.mytrial]
</trial>

<sound mysound>
/ items = ("mywav.wav")
/ volume = values.myvolume
</sound>

<text mytext>
/ items = ("Volume = <%sound.mysound.volume%>")
</text>

<text up>
/ items = ("+")
/ position = (50%, 45%)
</text>

<text down>
/ items = ("-")
/ position = (50%, 55%)
</text>

<text stop>
/ items = ("stop")
/ position = (50%, 75%)
</text>
By rburtonaus - 4/5/2014

Thank you very much. I posted after a day of struggling. Its a great relief to have something that works.