In response to Vorleak's post

Awesome post Vorleak. I'm really glad you posted about this because I got inspired and asked musician friends of mine on their opinion. My boyfriend who composes classical music told me about the "Shepard Tone," named after Robert Shepard.  In order to explain it technically, we would all need to understand composition terminology, but essentially, it is an auditory illusion that gives the impression as though a sound or upward/downward tone will reach its end. When you listen to a shepard tone, you either hear a falling or a rising in its tone and expect it to end but it doesn't. IT is explained as the following:

"The Shepard Tone fundamentally is based on sine waves. You start with a Sine wave say on note A4 which sits at 440 Hz and you have it glissando down to A3 at 220 Hz over a period of time. During the same time you have another glissando starting on A5 at 880 Hz and dropping down to 440 Hz.
If you were to repeat this cycle the glissando starting on 440 Hz would pick up where the glissando starting on 880 Hz left off. This creates the continued sensation of a falling pitch. However, if you repeat the cycle then you will quickly jump back to 880 Hz and will noticably hear it. So what do we do? In order to achieve a smooth and seemingly endless cycle we need to fade in the upper most glissando and fade out the lower most."
http://audio.tutsplus.com/tutorials/sound-design/sound-design-falling-forever-the-shepard-tone/
Here is a video of it if you want to listen. I think it's definitely a good representation of infinity through sound. Hear the illusion?