An analogue signal is any continuous signal for which the time varying feature of the signal is a representation of some other time varying quantity. A digital signal is a signal that represents a sequence of discrete values. The human voice is an analogue signal as the frequency of the sound varies. 
Music synthesis, speech recognition and even emotions detection through voice analysis is a small part of what Artificial Intelligence is capable of doing today. The possibilities are endless but, can Artificial Intelligence really listen? 
Asking this question leads to the realization that what we usually perceive as sound, has nothing to do with the sound itself but with the complex patterns that emerge from the context of it.
Now consider a box, or to be precise, consider a deterministic box. For now, every Artificial Intelligence algorithm, even the most sophisticated ones, are executed inside a box. We may be living in boxes, buying boxes, thinking in boxes but our feelings are natural and thus, non-deterministic. We express ourselves through ever-changing stochastic processes, and thus the assimilation of concepts such as fear, love and existence cannot be achieved from the inside of a box.
Can you really listen?