In the early 20th century, Argentina absorbed millions of immigrants, many of them Italians, who spoke mostly in their local dialects (mainly Neapolitan, Sicilian and Genoese). Their adoption of Spanish was gradual, creating a pidgin of Italian dialects and Spanish that was called ''cocoliche''. Its usage declined around the 1950s. A phonetic study conducted by the Laboratory for Sensory Investigations of CONICET and the University of Toronto showed that the prosody of ''porteño'' is closer to the Neapolitan language of Italy than to any other spoken language.