Hi all - I know quite a few of you have been experimenting with Intonia and other pitch-recognition / training software and I wanted to share some information with those of you who are Mac users, that may prevent you from pulling your hair out in the process.
There is a setting in Mac OS X v.10.6.8 (I am not sure of other versions) that will detect continuous tones (and pertinent to us: violin bow strokes) as noise and start to reduce the volume of this detected noise.
This will cause your longer violin strokes to be recorded with lower volume, and you may see this happening in the middle of a long bow stroke, like what Ray has mentioned in a previous post. you may be bowing with the exact same temperament and pressure (and therefore consistent volume), but with this feature enabled, volume will seem to be decreasing even though really, it isn't.
I would recommend that you un-check this setting when you are using pitch software. You may wish to re-enable it afterwards, especially if you use Skype or other video conferencing software, as it may be useful there.
The setting can be found under: System Preferences -> Sound -> Input -> "Use Ambient Noise reduction".
Good luck and happy fiddling!
Posted: March 13, 2012