@[deleted]: thanks for the answer. I don't think I'd consider dither an effect. It is a method used to reduce distortion when digital samples are requantized. From Wikipedia:
Dither should be added to any low-amplitude or highly periodic signal before any quantization or re-quantization process, in order to de-correlate the quantization noise from the input signal and to prevent non-linear behavior (distortion); the lesser the bit depth, the greater the dither must be. The result of the process still yields distortion, but the distortion is of a random nature so the resulting noise is, effectively, de-correlated from the intended signal. Any bit-reduction process should add dither to the waveform before the reduction is performed.
I'm still wondering if WavePad applies it or not.