# Aliasing in audio

Reading wikipedia to be sure and it says:

In signal processing and related disciplines, aliasing is an effect that causes different signals to become indistinguishable (or aliases of one another) when sampled.

Is it any signals ? or just high frequencies aliasing as low frequencies ?

It's generally stated as the high frequency portion of the original signal spectrum that moves (as a result of the spectral shift caused by time domain sampling) into a new position which is interpreted as the location for low frequency signal spectrum regions. Henceforth a high frequency signal owning the identity of a low frequency signal. However, it's also possible for the low frequency portions of the original signal spectrum to shift into high frequency spectrum regions which would happen for example at a sampling rate of $F_s = F_c$ samples per second, where $F_c$ is the cutoff frequency in Hz, of the original bandlimited continuous-domain signal. Therefore it's just an aliasing; where any frequency component can move into any where in the spectrum according to the given set of parameters $F_s$ and $F_c$