I don't exactly know how to describe this, but when I render notes with some resamplers it makes this robotic growling noise, here are some samples of what I'm talking about:
http://vocaroo.com/i/s0teCAUf8guN (tn_fnds)
http://vocaroo.com/i/s0fuYQ8VWh56 (TIPS)
The default resampler, EFB-GT...