Dithering modulates the least significant bit of the audio signal, so at normal listening levels it should be inaudible. Of course, one can amplify the silence by 120dB or so and hear the noise.
Sources: http://www.dspguide.com/ch3/1.htm
Sources: http://www.dspguide.com/ch3/1.htm
I think an additional layer of hiss would show up when it actually started playing.
Depending on how the original audio was mastered, it could also have it's own hiss in the sound data if the CD itself. You can tell if you load the raw CD data into a wave editor and see low amplitude noise where you'd expect silence.