Maybe the most common way tuning is thought of is to enable a series of harmonies or scales to be performed in as many different ways or in related ways depending on quite a varieties of approaches. Intonation regardless of the ‘school’ has given both melody and harmony new options as well as different stresses and pull even in sometimes the most familiar of material.
These explorations have lead to sometime unforeseen musical situations that result in acoustical phenomenon not sought for but compelling when it appears sometimes out of nowhere. More than a few have sought these events exclusively by means that can be as simple as close pitches creating beat and beat patterns, or proportional triads or larger units as well as difference tones. It we pursue this path and construct tunings to do so, might the term ‘tempering” not be the best term we might use.
I think what is happening in many of these cases in pursuit of both sound and noise is closer to what Cage described and did with the term “prepared” in the case of the piano .
The prepared piano was changed so that specific notes would be changed into specific sounds. In the field of intonation this shift goes from the noun of a singular pitch to the verb of the interaction of two or more, by interval. Being tied to ‘interval’ instead of a single atom of sound allows each individual tone to act potentially in a variety of roles that might be unique in its relationship and situations to the whole matrix of others. This places an overarching "political " framework by the roles each plays within its structure. It becomes capable of personality as well as identity. This approach calls for more investigation along these specific lines as these goals and desired will lead to new forms to have them realized. While we have new melodies and harmonies, we also have new sounds and even new noises and it is these four elements that promises much to the modern sound alchemist even via just the one parameter of tone.