Example:
Mottram (2020) shows that...
OR
...(Mottram, 2020).
Name of announcer. (Year, Month Day). Title [Radio broadcast]. Name of site. URL
Example:
Mottram, L. (2020, January 8). Hazard reduction burning is not a panacea to bushfire risk: Expert [Radio broadcast]. ABC. https://www.abc.net.au/radio/programs/pm/thinned-forests-can-be-more-prone-to-fire,-expert-says/11853280