It is a rich topic, one that does not receive enough attention in our training - we are saving time, after all.
In the tension between the two modes of hearing one experiences the liveness of sound, if I may call it that. It is as if sounds teeter on the brink of stability, longing to be stable but not quite "knowing how." What pulls the tones higher or lower is sometimes acoustical, a function of the instrument's mechanics, sometimes the feeling of the singer or instrumentalist.
Sometimes it is the composer's skill that exposes this quality where we least expect it, on the piano, for example. This morning I heard it happen in the Minuet of Beethoven's Op. 10, No. 2. Combine Ds and C#s in just the right octaves and proportions and, voila! the sound moves.
