2005, José Ignacio Hualde,The Sounds of Spanish, Cambridge University Press,→ISBN,page28:
Thus, whereas practically all Caribbean speakers [of Spanish] aspiratepreconsonantal and word-final /s/ [pronouncing it as [h]] to a certain extent (except, perhaps, for some radio announcers), this is a highly variable process and the highest indices of aspiration and deletion of /s/ are found in the most colloquial styles.