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I'm getting lots of 60Hz hum (with plenty of harmonics) in my EEG measurements and I'm wondering how to minimize that. I followed the directions of bundling the electrode wires together so that the hum is common mode and will be subtracted when one of the electrodes is selected as the reference. Thi...

Ok. But if I want to see the cochlear microphonic then that would show up in the "noise" trace?

I hope you don't mind me resurrecting an almost 15 year old thread. :) So you're saying that the "Noise" trace is created by subtracting, instead of summing, alternate stimulus sweeps. Does this mean that if I use an alternating polarity stimulus as is commonly done then the "Noise" trace is effecti...

Thanks again. The audio interface I have has DC-coupled outputs so I should be able to directly drive 5V DC. I'll probably add a current limiting resistor to be on the safe side.

Thanks. I will send an email. Also, is it possible to connect a sound card output directly to trigger pin1 on the 37-pin parallel port? Does the voltage need to be held high or can is it enough to just pulse? And how much measurement jitter and latency is there from when the trigger goes high? Is th...

I recently bought a used Active Two system. It came with various electrodes but some of them I'm not sure what they are for. The front panel of the A/D box has CMS/DRL in the first slot as is typical but in the second slot it has something labeled "LA RA LL" (and I have corresponding electrodes with...