Blanc was born in San Francisco, California to Russian-Jewish parents Frederick and Eva Blank, the younger of two children. He grew up in the neighborhood of Western Addition in San Francisco, and later in Portland, Oregon, where he attended Lincoln High School. Growing up, he had a fondness for voices and dialect which he began voicing at the age of 10. He claimed that he changed the spelling of his name when he was 16, from "Blank" to "Blanc", because a teacher told him that he would amount to nothing and be like his name, a "blank".

Blanc began his radio career at the age of 19 in 1927, when he made his acting debut on the KGW program The Hoot Owls, where his ability to provide voices for multiple characters first attracted attention. He moved to Los Angeles in 1932, where he met Estelle Rosenbaum (1909-2003), whom he married a year later, before returning to Portland. He moved to KEX in 1933 to produce and co-host his Cobweb and Nuts show with his wife Estelle, which debuted on June 15. The program played Monday through Saturday from 11:00 pm to midnight, and by the time the show ended two years later, it appeared from 10:30 pm to 11:00 pm.  With his wife's encouragement, Blanc returned to Los Angeles and joined Warner Bros.-owned KFWB in Hollywood in 1935. He joined The Johnny Murray Show, but the following year switched to CBS Radio and The Joe Penner Show.  Blanc was a regular on the NBC Red Network show The Jack Benny Program in various roles, including voicing Benny's Maxwell automobile (in desperate need of a tune-up), violin teacher Professor LeBlanc, Polly the Parrot, Benny's pet polar bear Carmichael, the tormented department store clerk, and the train announcer. The first role came from a mishap when the recording of the automobile's sounds failed to play on cue, prompting Blanc to take the microphone and improvise the sounds himself. The audience reacted so positively that Benny decided to dispense with the recording altogether and have Blanc continue in that role. One of Blanc's most memorable characters from Benny's radio (and later TV) programs was "Sy, the Little Mexican", who spoke one word at a time. The famous "Si ... Sy ... Sue ... sew" routine was so effective that no matter how many times it was performed, the laughter was always there, thanks to the comedic timing of Blanc and Benny. Blanc continued to work with him on radio until the series ended in 1955 and followed the program into television from Benny's 1950 debut episode through guest spots on NBC specials in the 1970s. They last appeared together on a Johnny Carson Tonight Show in January 1974. A few months later, Blanc spoke highly of Benny on a Tom Snyder Tomorrow show special aired the night of the comedian's death.  By 1946, Blanc appeared on over 15 radio programs in supporting roles. His success on The Jack Benny Program led to his own radio show on the CBS Radio Network, The Mel Blanc Show, which ran from September 3, 1946, to June 24, 1947. Blanc played himself as the hapless owner of a fix-it shop, as well as his young cousin Zookie.  Blanc also appeared on such other national radio programs as The Abbott and Costello Show, the Happy Postman on Burns and Allen, and as August Moon on Point Sublime. During World War II, he appeared as Private Sad Sack on various radio shows, including G.I. Journal. Blanc recorded a song titled "Big Bear Lake". Answer this question using a quote from the following article:

What did they talk about on the show?
Cobweb and Nuts