Millisecond Forums

Problems with sound stimuli

https://forums.millisecond.com/Topic17409.aspx

By xpsi - 10/16/2015

Hello,

I am using an Inquisit 4 web license and currently run a reaction time experiment with sound stimuli (all stimuli with the same volume). We tested the experiment multiple times on different computers and did not encounter any problems. Now, I received feedback from several participants (from an online pool) that they cannot hear the sound stimuli - either not at all or only in some of the trials. I have a probe tone in the beginning of the experiment to assure their loudspeakers are on. The problems seem to occur independent of their operating system.

I am wondering what might cause these problems and whether there are any precautions I could take to prevent them (except of making participants turn on their loudspeakers). I would be very thankful for any ideas on this!

By Dave - 10/16/2015

If your sound stimuli are not all encoded in exactly the same way, there is a possibility that some won't play on some machines because there is no proper codec available. Other possibilities are subtle mistakes in your scripts and user error (e.g. participants forgetting to turn on their speakers or muting them accidentally).
By xpsi - 10/17/2015

Sincere thanks for your fast reply! Fortunately, it works for the great majority of participants but I will keep on monitoring and recheck the other options.