It's called (I think) sound design. Changing parameters of a sound wave like filters, resonance, envelope, cutoff, etc, you can achieve desired sounds (you can

It's called (I think) sound design. Changing parameters of a sound wave like filters, resonance, envelope, cutoff, etc, you can achieve desired sounds (you can do that using a real synthesizer or a virtual one). In this case they're explaining how to make a bass sound (which is in the lower frequency of the spectrum)