Perception, reality and synesthetics
Human consciousness has evolved along survival lines. Our senses exist primarily to warn us of imminent danger, and our brain is primarily wired to process this sensory input in a manner that prioritizes threats. Humor, beauty, sensuality, pleasure and even raw emotion are learned, imprinted on us after birth. They certainly do exist, but they are far outside the “natural” blank slate state we’re born with. They’re all matters of perception.
When we re-wire our brains, whether its through the introduction of entheogenic substances (drugs) or guided self examination (meditation), we radically alter the way in which perceive the universe around us. When we become bogged down in endlessly striving for that which is “real,” we’re simply trying to go back to that emotionless, survivalist form of our newly-born mind. We can’t go back. We can’t kill off our hunger for beauty, wonder and magic. When we force our minds to stop working in the threat assessment mode and similarly force it to rewire itself, we are perceiving reality in a new manner. Sounds may indeed have “tastes” in this new perception of reality because we’ve forced our brain to process the signals in a manner in which they are not traditionally routed.
Venetian Snares and Aphex Twin have already demonstrated this.