Sir, surely you don’t imply that a computer can process that.
The physical substrate which executes the algorithm is irrelevant to the discussion. Indeed, even the fact that the signal represents sound waves is irrelevant. We could build a computer that executes the same instructions on the same inputs mechanically, using gears and valves and whatnot, or perform the instructions manually on paper, and the algorithm would result in exactly the same output.
You are wording things very strangely (E.g. “principle of electromagnetic action”, “quantities of motion”). This greatly hinders communication. Are you able to say things in a more normal way?
My guess is you are asking why they believe that the substrate the algorithm is implemented in is irrelevant. This is by nature of what it means to implement an algorithm. The same algorithm implemented faithfully (by which I mean, implemented such that it runs correctly, i.e. as specified) will behave the same regardless of the substrate, because what it means for the algorithm to run correctly is independent of the substrate. If it behaved differently in a different substrate, in that it gave a different output, then it would not be performing/implementing the same algorithm, by virtue of what it means to be implementing an algorithm.
The algorithm being considered must be considered in an applied scientific paradigm. One is not simply examining a mathematical operation, but one which is being examined to cause natural movement - unless you believe an algorithmic process is occurring with nothing correspondent to nature? To consider it irrelevant to the question of the fidelity differences in a spectrogram analog conversion and an MP3 - which I must remind reader entails the electrical signal output to something humanely resourceful, e.g. listening in headphones - is lacking in critical insight. This is after all the original question, and not an issue of algorithmic differences, correct?