In the golden age of radio (and possibly TV, I'm not sure) when the background noise of people milling about was needed (like for a crowd or party scene or a lynch mob) the actors would be directed to say Rhubarb over and over again with various vocal inflections, creating a blanket of nonsensical background noise.
Spike Milligan parodied this in various episodes of The Goon Show - the cast would do as described above, but because there were only three of them it sounded completely ridiculous.