Recent studies have called into question the traditional view that mutation of /p/ and /t/ is less widespread geographically than /k/ → [h], and in areas where the rule is not automatic, /p/ is often more likely to weaken than /t/ or /k/.
On the other hand, deletion in rapid speech always affects /k/ first and foremost wherever it occurs, but /t/ reduces less often to [h], especially in the most common forms such as participles ([anˈdaːho] andato 'gone').
The weakening of /k/ is a linguistic continuum in the entire Arno valley, in the cities of Prato, Pistoia, Montecatini Terme, Lucca, Pisa, Livorno.
In the east, it extends over the Pratomagno to include Bibbiena and its outlying areas, where /k t p/ are sometimes affected, both fully occlusive [k], [t], [p] and lenited (lax, unvoiced) allophones being the major alternates.
Although it was once hypothesised that the gorgia phenomena are the continuation of similar features in the language that predated Romanization of the area, Etruscan, that view is no longer held by most specialists.