The title of your link is “Perceptual attributes of acoustic waves – Timbre”. I believe you make my point right there but I will expand further.
You cite the following factors:
- signal time variance (envelope)
- degree of attack and decay synchrony of the sine components;
- presence or absence of high-frequency inharmonic energy in the attack portion of a signal;
- spectral energy distribution (frequency, amplitude and phase values of the sine components of a complex signal - may change with changes in intensity and register, even for a given instrument); and
- spectral energy distribution time-variance (spectral flux or "jitter").
Where in the article does it refer to something other than a waveform?
a. The “signal” is a waveform
b. “Sine components” are only found in a wave
c. “inharmonic energy” refers to waves
d. “Frequency amplitude and phase changes of the sine components” refer to waves
e. and from the article itself: “Helmholtz was the first scholar to link timbre (a perceptual aspect of sound waves) to spectral distribution (a physical aspect of sound waves). He specifically focused on the spectral distribution of the steady state portion of sound signals (defined below). This approach overlooked several acoustical aspects of sound signals, such as attack (onset transients) and signal/spectral time variance, both of which have been proven important to timbre perception.”
Where do you think onset transients or signal/spectral time variances are found, if not during the delivery of waves? These are not created in one’s head.
Regarding crosstalk, it is defined by Wikipedia as “usually caused by undesired capacitive, inductive, or conductive coupling from one circuit or channel to another.”
Meaning that the electromagnetic waves created in one wire impact the electromagnetic waves in an adjacent wire, thereby making it different from the original signal. Crosstalk is an example of electromagnetic interference. Waves again.
Referring to psychoacoustics, Ansys.com states: “Psychoacoustics is the study of how humans perceive sound. It’s a relatively young field that began in the late 1800s to help aid in the development of communications. Psychoacoustics combines the physiology of sound — how our bodies receive sound — with the psychology of sound, or how our brains interpret sound.”
Our stereo systems can only address what sounds (waveforms/signals) our body receives. As I said earlier, once it hits the brain, the damage is done. Your brain cannot repair what was missing from or added to the original signal. It can interpret it, but it cannot change it. That has to happen before it gets to the eardrum.
You finish with: “No audio system is perfect high fidelity reproduction ... They all translate in a relative way some experience, timbre and spatial acoustic qualities, which are not reducible at all to signal noise ratio on a line”.
First of all, they are reducible, but only in part. The other influence is the speaker’s interaction with the room and that is why I continue to emphasize that to get the best signal/waveform to your ears, you need to address the signal in the room as well as in your electronics. What happens to the signals in your head is your problem and yours alone.