Comment Re:methodological curiosity (Score 1) 256
1) The only part that requires millisecond level precision is the production of the two FM sweeps and and quiet period between them. I'm not quite sure how to answer your question (and others here) any better than that - once it's clear that it's not response time that we're trying to measure with ms precision, I hope it makes sense that sending a single array representing the sound waveform (2 FM sweeps and the quiet period between them) to the sound system without introducing any jitter is relatively straightforward.
2) In a on-line version there is no control, of course, over what else the user is doing, so it is possible that other processes will interfere with the timing and reduce the accuracy of the test. Several people here have commented on hearing clicks and so forth, which could be do to this. There's nothing to be done about it. When we collected our normative data, we did it with participants in front of our computers in our lab to ensure that no extraneous processes contaminated the data set.
Henry
