From Chuck Vaughan - If you go to the Windows Audio Control Panel and change the sample rate of the sound card from 44100 to (e.g.) 4800, you get a pop/snap sound on the leading edge of each element.
On my Win7 system, this is the DEFAULT format. The keyer and news set their own explicit format: 44100/16. Or maybe you're referring to some lower-level hardware setting on the sound card? I'll try to contact you via email.
The audio control panel sets the default rate, but these apps specifically set their rates to 44,100. I cannot see any difference when the audio control panel is set to 48,000.