Using Synthesis to Create Original Sounds

Question

Many videos I've watched on synthesis aim at emulating physical instrument sounds (or sometimes physical sound effects), with the pursuit of realism as a guiding principle. At first, this struck me as something in the neighborhood of a skeuomorph. I wondered why the contingent attributes of physical objects should dictate sound design principles now that their limitations can be put aside using synthesizers, whose space of possible sound outputs is much larger (at least if we ignore differences between indiscernibly similar sounds).

Later I discovered the answer that our ears have evolved to appreciate the sounds physical instruments and objects can produce, because they have been with us for so long, but I still wonder how musically useful synthesis can be for producing original sounds rather than emulation.

1. Very qualitatively, what percentage of possible sounds a synthesizer can output are viable for music? I know an exact numerical percentage would depend on way too many factors and boundaries, but I just want a general sense of how sparsely musically-viable sounds occupy the space of all producable sounds.

2. Again very qualitatively, what percentage of those musically-viable sounds correspond to sounds produced by physical instruments or objects? Is that evolutionary correlation between the ear and the physical so strong that it accounts for nearly all of our ability to find pleasure in musically viable sounds, or does synthesis unlock a large amount of musical potential not grounded in emulation of the physical?

3. If synthesis does open these original avenues, is there a field of study which teaches how to create music by designing these original sounds, rather than by emulating physical instruments or objects?

Answer 1

No.1 is easy to answer: every conceivable sound has a potential musical use, so of course that includes any possible synthesizer sound.

No.2 is unanswerable without a rigorous definition of what sounds correspond to physical instruments

No.3 is easy: the field of study is called "synthesis". The emulation of physical instruments is just a small part of the field.

Answer 2

This seems like a lot objective and qualitative questions surrounding a subjective core: the phrase "musically useful." For something to be musically un-useful, a host of assumptions about aesthetic context and aim come into play. (Cue a reference to Hindemith and "Music for use?") Synthesis was born and evolved through experimentation and trial-and-error, which always means pursuing some avenues without being convinced of their usefulness beforehand. As PiedPiper also notes, the distinction between sounds that emulate physical sources and those that don't is a difficult and fuzzy one, especially if we're talking not just about intent but about product. If a bass pad, created without intent to emulate, happens to be "indiscernibly similar" to a foghorn, does it count as matching a physical source?

(Here's something to muddy the philosophical waters: what happens when we use physical objects to emulate electronic sounds? https://g.co/kgs/wAw3vn)

It seems that there are two seeds to your post: Issues of intent and guiding philosophy in the pursuit of synthesis ("Why are we so hung up on emulating physical sources?"), and speculation about psychoacoustics ("Have humans evolved to respond more strongly to physical sources?"). Stripping away the subjective, my answers would be:

• I don't know that the field of synthesis is still disproportionately emphasizing emulation. Can that be shown?
• I think the question about human response to physical sounds rests on too tenuous of a distinction between "physical" and synthesized sounds. There is study into human response to certain frequencies, often accompanied by speculation about evolutionary explanations. But I think it would be hard to test "artificial" sounds (especially since we've been acclimating to artificially reproduced sound since the late 19th century).