The National Sound Library of Mexico has found an audio recording of what is most likely painter Frida Kahlo reading her essay "Portrait of Diego" in the early 1950s. It was recorded for the pilot episode of radio show El Bachiller. From The Guardian:
The episode featured a profile of Kahlo’s artist husband Diego Rivera. In it, she reads from her essay Portrait of Diego, which was taken from the catalogue of a 1949 exhibition at the Palace of Fine Arts, celebrating 50 years of Rivera’s work…
In the press release, Mexico’s secretary of culture, Alejandra Frausto, said if it is indeed Kahlo’s voice – a claim which authorities continue to investigate – it could be the only audio recording of the artist that exists…“Frida’s voice has always been a great enigma, a never-ending search,” (library national director Pável) Granados told a press conference. “Until now, there had never been a recording of Frida Kahlo.”