I am not only curious about speech, but for concreteness in illustrating my question, I consider the case of speech perception. Assume a listener is presented with an acoustic waveform. The wave causes deviations from the atmospheric pressure at the listener's eardrum. Thus, the acoustic pressure as a function of time “comes for free”, so to speak. Mechanically so.
From sound pressure we can derive amplitude, and by the fourier transform, amplitude as a function of time is transformed to the frequency domain. That is, amplitude as a function of time becomes amplitude as a function of frequency. We use this transformation because it reveals properties of the wave which are perceptually relevant, e.g. formant frequencies. Presumably, listeners can attend to properties of the waveform describable under this transformation.
But what about mathematical models of the acoustic wave which are not simply transformations on the wave, but which derive some richer structure from amplitude fluctuations over time. For instance, what about a model which constructs a higher dimensional representation of the wave from the one-dimensional pressure fluctuations? (Imagine that instead of amplitude being a point moving back and forth along the real number line, the wave is represented as a point moving around in, say, 3-dimensional space). Say that such a model revealed a perceptually relevant property P of the waveform. Would the listener be able to “hear” P directly, or would would she need to engage in some information processing task to recover P from pressure fluctuations over time?*
*I realize that human listeners don't actually manipulate equations in their heads. I use the mathematics just to describe the underlying neural computation.