poor voice response time resolution (case 14820)

Our lab collected a large amount of word naming latencies using Direct RT 2012 and a headset microphone. The computers are newer Dell desktop units. Problem is there is a clear evidence +/- 30 ms buffering going on in the sampling. Any ideas how this could come about, its as if we were using 1980's equipment. See attached histogram.

The only thing I have come up with is perhaps my students have plugged the mic into the front of the PC, and perhaps that jack does not use the main sound card? Otherwise, I have no clue. Please help!

Could you please either upload or send to [email]support@empirisoft.com[/email] a copy of your input and output file(s) as well as your styles.drt file?

Hi, I have attached the requested files. SAW1 and SAW2 refer to two separate conditions, that concern the presentation order of the items. Please let me know if there is anything else you need.

Could you please upload the corresponding long output files for these input files? You will find them in the log folder in the Data folder.

I have attached the requested log files.

Have you seen this latency in response times on more than one computer? If so, could you please send us a dxdiag.txt file for each machine? You can create it by clicking on the Start button, typing dxdiag in the Search box, and then running the dixdiag.exe application. This will let us take a look at the sound hardware and software that you are using.


Also, is there a way that you could connect the microphone directly to the sound card, maybe a port on the back of the computer? This would be a good test to see if the connection port you use on the front of the computer is part of the observed reaction times.

It turns out that the microphone was plugged into the back of the machine when the data was collected. The sound card hardware is just the default hardware that is included with the Dell machine. The config files you requested are attached.

Could you please specifically say how many computers are reflected in the histogram from your first post? Is it just for one machine or a combination of machines? If we are dealing with more than one computer, does the histogram you posted look similar across all the machines?

Could you please clarify exactly what is being graphed in the histogram in your first post. That is, what are the exact labels you would give each axis? What specific column of which data file(s) are being graphed?

The X axis of the histogram is pronunciation time, on a millisecond scale, observations start at 0 and range up to 1600 ms. The Y axis is the frequency with with each interval of pronunciation time was observed. The data are collapsed across about 40 participants, which is why there are such large frequency counts.

Could you please upload the data and syntax/procedure that you used to create that histogram? I would like to attempt to recreate it, especially because all of the 0 values from the x-axis are confusing.