The period following that has been called the golden age of Italian-language radio. From 1920 to 1950, it was possible at almost any hour to find some kind of Italian radio broadcast. New York City for example, had four stations (WHOM-AM, WOV-AM, WEVD-AM, and WBNX-AM) which carried significant Italian programing. Other smaller markets with population densities also had their own local outlets.In Philadelphia Italian radio programs aired on Philadelphia’s 10-watt WABY-AM, which is not to ignore the programs on WPEN-AM in Philadelphia and WAAB-AM in Boston
In New York, Italian-language radio began in 1916. That year WGL-AM was bought by John Iraci, a Sicilian-born importer. Iraci changed the call sign to WOV-AM. The last movement in that era was probably the flip at WHOM. In 1946 two Italian newspapermen purchased WHOM and converted the programming to Italian. In between those two bookends it's important to note that there was political suspicion of Italian-language programming because of Mussolini's fascism, and role in WWII. In 1935, at the height of WWII, Italy nationalized Radio Bari and Radio Roma, putting them under the direct control the Ministry of Press and Propaganda. They began airing anti-British messages. Signs were put up in US Cities "Don't Speak the Enemy's Language." It didn't just mean German and Japanese, it also meant Italian. Under the Sedition act, U.S. agents rounded up Italian nationals suspected of disloyalty.
Only when the pope threw his weight behind the allies did that American prejudice finally fade. (Not that there weren't pro-fascist broadcasts in English, ex. Father Coughlin) but race played a notable role in that era.) Over the subsequent decades,studies by Churchhill (1940) and Roche(1982) found a huge change in the listening habits of ethnic and particularly Italian-American citizens. They sampled groups in New Jersey, New York and Providence and found that successive generations were markedly less likely to listen to ethnic programming. They essentially proved that their cultural Americanization was a rapid process.
In the early 1950s Italian radio was in decline. Even WOV began to change. Programs like La Rosa, La Famiglia Rinaldi, Buon Pranzo, La Colpa E' Della Radio, and Donna Billonia faded away. The few FM stations carrying Italian-language programming gave hours to the Italian programs while AM stations began to take aim at Hispanic markets. In New York WHBI-FM and in Philly’s WDAS-FM took on Italian-language programs. But As FM rose in prominence over AM, those hours dried up as well. Ethnic programming migrated back to AM, but the decline was terminal.